You want advice, I'll give you some gold.
First, never, ever be embarrassed about your size or anything about being chubby/fat/obese. You're doing this because you're living your life on your terms and doing what you want.
Get a lot of food that you like and is easy to eat. Here in the U.S. there's Little Debby Cakes which are great to eat one box at a time (each box has like 8-10 cakes in it). And they're only a dollar or two.
Mix it up, variety will keep your appetite interested. Salty to sweet, different foods, etc. Keep snacks in every room. A fridge by your bed if you can. Eat how your body responds best- graze all day, or stuff at meals. I would recommend at least 2-3x/wk a good stuffing where you have a hard time breathing, but not all the way to nausea-you want this to be fun!
A big bowl of ice cream before bed every night. Search on the web for diet articles "Don't Eat These Items" or "10 Worst Foods for Losing Weight" and make sure you get lots of everything on those lists. Pizza, ice cream, brownies, etc. Lots of carbs and fats. Protein is not a priority at all.
When making a gain shake, get Cytocarb or some other carb powder (not protein). It's good for putting fat on you.
There's a lot more, but it's a good start!