Miserable 2nd Trimester!

I hate to be complaining about all of this but I KNOW there are others out there that HATE being pregnant too! This is my 2nd pregnancy and I'm 37--I was overweight when I got pregnant unexpectedly. The 1st 17 weeks I was nauseas and throwing up all day and I started showing way earlier than my first--I am 19 weeks now and cannot fathom how I am going to physically handle getting any bigger. I can't bend over, I am extremely SOB, in pain constantly (back, neck, pelvic pain, knees, ankles, etc) and can barely go for a walk. Sleep has been a major issue for at least a month now and I know all of these issues get much worse and that is why I am freaking out. Unisom doesn't help at all. How do you all cope?? (besides the fact that there will be a darling baby at the end that will make it all worth it lol!) I literally feel like all I can do is lay around and everything is 110% effort--all while chasing around my 3 year-old son. I try to be active and do light workouts and will be in excruciating pain that night and won't sleep at all. I feel like doctors just shrug and pretty much tell you there's nothing they can do, which is even more irritating--not to mention all the apps that keep saying "the second trimester is when you feel so great!" Ugh. Thinking about this only being halfway over gives me serious anxiety...thanks for listening :-)