Prozac is a more stimulating antidepressant than Zoloft, as such it tends to not be as effective as
Zoloft and other ssris
for anxiety generally, but you may respond differently. If it works, it's a good one to be on, as it's the easiest to stop taking as it lasts a lot longer in the body and therefore gives the body time to adjust if you stop taking it. But nobody can tell you if you'll gain weight on it -- everyone is different, so only trying it will tell you that. Good luck.