My son is 2.5 and is highly allergic to milk. He can't even have anything with traces of milk in it. He is also allergic to eggs and nuts.
Do you know if your son can have soy lecithin? It is an ingredient in many of his snacks and foods, so if he can't have it, you'll need to rethink my ideas and read labels carefully. Here's a lot of his favorites, including things he could eat at 13 months:
Snacks: cheerios, life cereal, rice krispies, Gorilla Munch (Trader Joe's), Gerber Puffs, Annie's Brand Bunny Crackers, Graham crackers (cinnamon flavor), Gerber fruit strips
Meat: chicken - stir fried and cut into very small pieces with a wide variety of sauces - teriyaki, bbq, soy, Italian dressing; ground beef, ground turkey, pork, hot dogs, Turkey meatballs from TJs, fish sticks (read labels carefully), chicken nuggets (read labels carefully) - Ians brand is good but expensive, as is Dr. Praegers
He loves fruit - just about any kind of fruit, cut into small pieces. He also likes fruit cups in gel and applesauce
Soy yogurt (might be too much soy for your son)
Breakfast - Vans brand and Whole Foods brand waffles, sausage I also bake a lot for him and then freeze it - lemon muffins, coffee cake, cornbread (I can email you recipes if you want)
Veggies - corn, peas, anything steamed - carrots, broccoli, spinach, squash, cauliflower, etc
Each meal usually has a meat, a fruit, and either a veggie or crackers/bread of some sort
I hope that helps. I know it's hard now, but it does get easier!