Bipolar Depression

He suffered depression about 10-12 months ago and dr put him on
lexapro meds started working within a week, he was happier and more
sociable. jump ahead 2 months and he is a completely different
person, wanting to go out all the time, bars etc. which we stopped
doing 7 years ago when I became pregnant. He made a bunch of new
friends on facebook, people like 10 years younger, he was litterally
crawling to get out of our house. he didin't want to work anymore,
didn't want the pressure. Started having an affair in the begining
of Janury, I didin't find out till about 3 weeks later. got a 2nd
cell phone to talk to her while I was working 12 hours a day to try
to support my family. he finally told me about the afair and said he
had to move out and explore the relationship. He has gone on
spending sprees and has loss of memory. our son is having a very
diffult time dealing with this I am speaking with his ped to get him
some therapy. Husband finally agreed to go see his dr and his doctor
thought he had bipolar, weaned him off lexapro and started him on
amblify. not really any change in him so far. dr sent him to see a
psy. dr and his diagnosed him as unipolar manic no lows only highs.
started him on a new med, I don't know the name as I am not to know
anything anymore as this is his life and he wants me out of it. I am
getting ready to file for divorce which he told me to do, he wants to
live his life, he feels 17 again and his ego is out of control,
thinks he is god's gift now. my question is, is there any chace the
guy I married and loved for 9.5 years will ever come back or do i
divorce and move on with my life???? thanks for letting me vent and
any advice would be appreciated. oh and by the way he has no
remorse, thinks that everything is ok and said that our son will get
over it and that I should get a grip and stop being emotional. I
should't be upset or cry.