Gaining

If you've been here for eight years and still aren't sure.

Just stick to roleplaying.

I just ate takeout like pizza, Mexican, Thai, burgers and such often and watched tv.

Stuff like heavy cream and that never appealed to me and upsets my stomach.

I have had success with just overeating. Try adding an additional meal, later in the day or have a second breakfast of donut/pastries.
I gain easily given I'm old. This summer I binged for three days and gained over five pounds, getting up to 230 lbs. (I'm 5'11", my waist was nearly 48". I stayed that heavy for several weeks. I have since dropped some weight, it's just easier to bend down, tie shoes etc. Good luck.