am I gaining weight?

So I can not tell if I am bloated or if I am gaining weight. This has been very frustrating for me because I miss my normal flat tummy. 
I do struggle with constipation (dumbest side effect ever). I'm also on other meds such as antidepressants etc. so, that's a reason I deal with dehydration and I do realize that it is important for me to stay hydrated. It's hard to just drink massive amounts of water for me at least. I don't know why.
Anyways, I'm just wondering what the best way is to get rid of this bloating? My body has looked bloated for awhile now and can't tell what's going on exactly. And I know I'm not pregnant. I took several tests.
Does anyone have an idea?☹️