I'm sorry you and your little one are suffering so - having a new baby is intense enough even when everything is going smoothly, and then to be trying to comfort and soothe a baby who is in chronic physical pain (vomiting, sleep issues, likely intestinal and skin issues as well!) is incredibly emotionally and physically draining for parents. BTDT myself and really feel a lot of empathy for you and your baby and your family!
First, please please continue breastfeeding your baby if at all possible -- however, you will very very likely need to alter your own diet to eliminate the foods that are probably transferring to your son via breastmilk & aggratvating him. From my experience, THIS IS WORTH IT and typically pays off TREMENDOUSLY in terms of a healthier, happier baby (and mom and family)!
My 2nd, also a son, had very similar issues, was also exclusively breastfed, and when you see just how vastly they can improve with relatively small/simple changes to mom's diet, it can be VERY motivating! And this coming from a mom who *really* loved her milk, cheese, yogurt, ice cream, etc. :) It helps to remember that babies don't nurse forever, so these dietary changes are temporary - in the grand scheme of things, 12 months without any cow's milk in your diet is small compared to the huge number of non-nursing months in your life! Plus, you have such a valuable window into your son's health, what you might be in for when starting solids, what to look for, etc. in terms of possible future food sensitivies or allergies.
So, a few resources that helped me immensely -- please read over these and see if there's anything that could be helpful/applicable to you & your son (in no particular order, each helpful in different ways):
1) Food Sensitivities in Breastfed Babies
http://www.kellymom.com/babyconcerns/food-sensitivity.html
2) GERD & The Breastfed Baby
http://tinyurl.com/7wmhek
3) Pediatrician Dr. Jay Gordon discusses breastfeeding, cow's milk proteins, and symptoms of babies who are sensitive to cow's milk protein (CMP)
http://www.drjaygordon.com/development/pediatricks/dairy.asp
4) A long article from Pediatric Nursing, excerpt below is from p. 3 (http://tinyurl.com/8rs467 ). CMPI is cow's milk protien intolerance, CMA is cow's milk allergy, and this is often either the cause of or at minimum an aggravating factor of GERD:
"The research reveals that CMPI is found in up to 50% of infants diagnosed with gastroesophageal reflux (GER) (Salvatore & Vandenplas, 2002). GER is defined as the involuntary passage of gastric contents into the esophagus and is classified as either primary physiologic, primary pathologic, or secondary GER (Salvatore & Vandenplas, 2002). Usually, there are clinical manifestations in only one system of the body (GI) with primary GER. If more than one system is involved (GI, cutaneous, or respiratory), it is more suspicious of primary CMPI. Secondary GER is known in the literature as GER disease (GERD), and CMPI is often its causative agent (Salvatore & Vandenplas, 2002). Vomiting and irritability seen in CMPI is sometimes mistaken for the vomiting and irritability often seen with GERD. However, the infant will have relief of symptoms when CMP is removed from the diet. CMPI often precedes gastrointestinal problems and should be ruled out as the underlying pathology of GERD (Staiano et al., 1995). Table 3 lists the symptoms of GERD, CMPI, and their overlap. "
5) Final resource that was a HUGE support for me was an email list of mothers who were mostly (98% of them) breastfeeding, trying to help their babies who had food intolerance, food allergy, reflux, GERD, etc., and were supporting one another through the dietary changes. These ladies kept me sane, and there's a WIDE range of experience on the list. Take what works, leave anything that doesn't resonate with you -- the list is an awesome place for support, encouragement, help modifying recipes, and tips for navigating family and social situations in which others aren't aware of or savvy about dealing w/ food/digestive issues. The name of the list is The Foodlab, and here's the link -->
http://health.groups.yahoo.com/group/foodlab
I recommend choosing "digest" format for email delivery from foodlab, or at minimum filtering all emails from this list into a specific folder. And certainly, please introduce yourself and share as much about the GERD issue as you'd like, asking any questions you're currently having about nursing a sensitive baby.
Last but not least, I really, really want to acknowledge the VERY big effort you've been putting forth in trying to help your baby, breastfeeding through it up to this point, and recognizing that you're at a point where something needs to change for the sake of your own sanity and your entire family.
I personally was blown away by the HUGE role that moms can have in *healing* their GERD/reflux-y/colicky babies w/ some strategic dietary changes (for mom) and the wonderful properties of breastmilk (for both mom and babies w/ gastro or immunity/allergy issues). While formula might seem easier right now, I have met too many moms in this situation (as I was once there myself!) who went to formula only to find that the cow's milk formula made it worse, followed by a switch to soy formula that again was contributing to the problem (50% of babies who are sensitive to cow's milk formula are ALSO soy sensitive), only to move to a SUPER expensive "hypoallergenic" formula such as Elecare or Neocate -- at this point, their breastmilk production had decreased greatly and a LOT of work went into pumping to get back their supply that they regretted having lost in the first place when trying "the formula shuffle" out of sheer desperation (which again, I empathize with that too!). Instead of searching for formula, if you can hang in there for another 10-14 days of breastfeeding, pour your efforts into tweaking your own diet -- and by all means, seek out support from a group like Foodlab for help w/ the dietary stuff. If you are really beyond exhausted and cannot stand breastfeeding for one more minute, I highly encourage you to insist on switching to a hypoallergenic formula first (like Neocate or Elecare) for a few weeks, watching for your baby's symptoms to hopefully improve, and *then* maybe stepping back down to a soy or cow's milk formula (again, watching for reactions/symptoms to crop back up).
Will end here, but just hoping so much for you that your baby starts to feel better ASAP! :)