Help me gain weight 😫

I finally got up to a weight i was really happy with around 6 months ago. I'm almost positive it was bc I had started smoking weed on the regular and had a healthy appetite. I quit smoking completely in Aug and I did notice a change in my appetite, so between that and stress, it's pretty much non existent now. I snack a couple of times a day and that's about it. I knew I had lost a little weight but it never hit me hard until I saw a friend last week and she mentioned it. Then my mom mentioned it. & now I just put some shorts on that use to be really tight, and now they're about two inches too loose. 😒

I have no idea how to increase my appetite, so any ideas would be super helpful! & Ideas on the best foods to eat and possibly vitamins to take that can help put the weight back on.

😫😫