I am in a constant battle to put on weight and keep it on, but probably for different reasons than you: I am on HIV medications that initially gave me mild nausea but as I grew accustomed to them, just suppress my appetite.
On advice of doctors (and other people living with HIV) I buy those meal replacement powder mixes (cheaper and better tasting than Ensure and have them in addition to three or four regularsmall meals a day. Anytime I am thirsty I l mix up a Slimfast and drink that (instead of just milk). Ensure is not as foul if you add Nesquik.
I choose meals with a lot of strong flavour(s) - small several moderate portions of each thing . I never overload a plate because the sight immediately kills my appetite
Always have breakfast. Have lunch. Have a 4:00 snack.
eat dinner at 6:00
snack on cheese and mug of soup while I watch TV in he evening. A snack at about 10:00 p.m.
All of this just keeps me from losing weight .
Be aware that smoking cigarettes is an appetite suppresant (which is why so many models and dancers smoke).
If those things don't do enough (as they do not for me) see if the laws where you are (and your doctor believes in it) ask if medical marijuana is indicated in your circumstance.
Bear in mind though that smoking it also introduices a lot of tar and crap into your lungs, so there is a health trade-off to discuss with your doctor.
Synthetic THC in pill form (called Marinol) is available and gets around that, but it is VERY expensive (at about $1,000 for a month's supply in Canada).
It is not something you want to do for the "high" - and if it is, you are probably not a good candidate for it.
The choice i have is potentially health-threatening ongoing weight loss or possible lung cancer in my future. reducing that risk is I do not smoke cigarettes.
Marijuana is generally prescribed only for a short list of qualifying medical conditions - none of which you want to have just for the sake of being able to smoke pot legally.
Feel free to PM me if you want to know more.