Off of meds and feeling huge!

Hi! This is my first child and my fiancé and I did not plan it. So I was on my normal medication of 80 mgs of Prozac (antidepressant) and 50 mgs of vyvanse in morning and 20 mgs of adderall in afternoon. I’ve been on this ADHD and antidepressant medication for almost 10 years, so going off it when I found out I was pregnant, was hard but I was able to do it. What I didn’t notice, while going off this medication, was how much weight I gained. I have always been in great shape- high metabolism and working out intermittently. Since I have been pregnant and gone off medication, I have legitimately blown up. I am 20 pounds heavier already and only in week 11 of my pregnancy. I have tried curbing my eating (which has been almost impossible because eating has been my way to prevent nausea) and being more active (also hard when I’m non stop tired). Has anyone else had a similar experience?? My doctor says I’m fine but I can’t even fit into any of my clothes, have zero sex drive, and am pretty much hating most of this pregnancy.