I know how you feel, don't worry, you're not the only one. It's just the trials of motherhood. A lot of kids have a hard time with sleep. It can be scary, especially when they're in pain and they don't know how to soothe themselves. I have 2 kids 4 1/2 and 16 months. My first was a real challenge. I still have issues to deal with, but it's mostly because I was a little too soft in the beginning and it allowed her to realize she had this power over me and she used it. so I had to develop my own technique that has evolved over time. With my 2nd, i got it pretty easy, but I've still had to see him through many nights of tooth pain. But otherwise I made sure to be consistent and firm with him so that he couldn't find my weak spot. so I've been all over the map on this issue.
Maybe he needs a soothing, reassuring routine that leads him into sleep. A little while before nap time find something quiet for the 2 of you to do together, like reading a book or looking out the window. Then offer something to drink or even a small snack if he wants. Then while he's doing that, start saying something about naptime, like, When you're done eating it's time to take a nap. you need to rest and then we can play some more. Then when he's done eating or drinking check his diaper and make sure he's wearing something comfortable to sleep in, and rock him a little in his room. Maybe even quietly talk to him about how tired he must be and make him feel all warm and fuzzy. then try to put him down and rub his tummy or back and say real gently It's time to go to sleep now. Try walking out, and shutting the door. Wait outside to see if he keeps crying, then if so, go back in and repeat from the rocking point until he gets tired enough or you give up and let him sleep on you. then you can just try it again the next day. It'll be really hard at first for both of you, but if you come up with your own routine and stay consistent, it'll work it's way out. For nighttime, just try the same thing but add a bath in to give him a warm sleepy feeling. Then eventually he gets the steps and can calm himself down cause he knows what's coming. I understand your feeling toward crying it out. i could never do it either, but when what you're doing isn't working for you then you know you gotta make a little change. The longer you make it easy for him to take over your time and be dependent on you to fall asleep, the harder it is to make a change when he's older. If you take little baby steps away from the situation now, you'll find it much more manageable than later. You just have to be willing to do things that may seem uncomfortable to you at first, but it will get easier for him, which will make it easier for you. Whatever methods end up working doesn't matter, the point is to make him feel like it's okay to go to sleep and that he's safe. But I admit that when my kids are sick (teething can make you feel real lousy) I indulge their need for comfort and sometimes lay on the couch with them so we can get a better night's sleep. Just make sure to get back to the routine and be firm once you know they're feeling better. I hope this helps, and remember this all passes in a blink of an eye!
P.S. I just read your other request about the breastfeeding biting problem and I just made the link with his sleeping problem. Of course! He's even more upset bacause you're withholding the breast, his best source of comfort. I don't know if it's too late for this, but I have some advice on biting. Instead of pulling him away, push the back of his head toward your breast. I know it sounds weird, but it forces him to open his mouth so he can't bite and you can pull out with out getting hurt. Then you put him down and let him know that's not okay. So I know you said you were thinking of weaning anyway, if you think you wanna try it again, you could approach it more slowly while getting him through his bad teething right now. But if not, you need to definately replace that source of comfort with something new that will help him sleep easier. Sorry so long winded, I just really feel for you.