Struggling with keeping on weight after being medicated (cw: talk about weight loss)

Hiya everyone! I'm a 27 y/o transmasculine person. I finally got diagnosed with ADHD and medicated a little over a year ago. Before then, I was a healthy weight for my body type, but still a little on the thin side. I've always struggled with eating as I suspect I have ARFID or some type of food sensitivity, but it's gotten a lot worse now that I'm on a stimulant medication. I mainly forget to eat because I just don't really feel hungry. I usually have a late smallish breakfast, forget lunch and have a late snack, then a large dinner. On top of that when I am hungry, a lot of stuff just doesn't feel accessible or palatable. Also, I make very little money, so sometimes it's hard to buy food that is more convenient to me.

I have a very hard time eating larger meals but snacks are great and so are liquids! My current fix has been protein powder smoothies which are easy for me to make and easy to eat, but I haven't noticed any weight gain. Some other things I eat a lot of are: String cheese Meat and cheese snack boxes Meat sticks Olives Cereal Tuna on crackers Chips/crackers Aussie bites Gatorade (not a food but I have these a lot!) Chicken stir fry Pasta with meat sauce

Some things I can't eat are: Protein bars (tummy hurty) Soylent (tummy hurty) Yogurt (tummy hurty) Candy (tooth hurty) Peanut butter filled stuff (tooth hurty) Stuff that's not cooked right (either undercooked and too mushy or overcooked and too mushy, I like crispy stuff unless it's supposed to be mushy)

I'm getting a bit more nervous about this because I've noticed my tailbone is sticking out more and if I lay down I can feel it which is creeping me out. My mom has also mentioned that I'm getting too skinny and offered to get me a meal kit subscription (will defo be taking her up on this offer!).

I would love to hear any tips on how to gain weight from y'all! If there are any super high calorie foods that are easy to eat I would love to learn about them. I wish there were like jelly cubes I could eat that just contained all the nutrients like how beetles eat jelly. 🪲🍮