Hey Jas! It sounds like you are doing great! From what I've read on this forum, strange sensations are not uncommon for quite a while after surgery. So if your CRS said your butt looks great, then I'd say you're doing brillaintly! :D
I'm sorry I don't have experience with Lexapro, but I was also given anti-anxiety and anti-depression meds and they really helped. I think you'll find that things will begin to improve dramatically once you take the meds and very soon you'll be able to taper off them and put all this behind you.
One thing you might find with the metamucil is that it can make the stools pretty bulky - they'll still be soft, but they could be bigger, so don't panic. Remember to still drink LOTS of water when you use that stuff. :D