05 trailblazer 4wd transmission problems

I have an 05 Trailblazer with 4wd. I’m having an
issue and not sure what’s wrong or where to start. I
have a Code reader and it isn’t throwing any codes
my alternates went out a few months back and
killed my battery.parked the vehicle for a few
months. When I got the extra money  I bought a
new battery. Had the oil changed and fluids
checked and filled it up with fuel. Drove it about an
hour away and on my way home it revved a little
high going up a hill. Kinda felt like a slip in the trans.
After getting it home with no other issues I pulled in
and out it in reverse to back into my parking space
and it wouldn’t budge. I put it back in drive and it
would only move a little. It will only rev up to 2k
rpms Even in Park. In reverse it won’t budge at all!
When it sits for over 24 hours the battery dies
despite everything being off. ( not sure if these
issues are related)

When I shift it out of park you can’t feel the
transmission change. I’m not sure if the reverse
lights come on when in reverse as I’m alone and
can’t check them. Any ideas on what this issue
could be or where to start on a minimal budget with
3 small kids. I don’t have the money for a trans
repair shop or to have it towed. If I could figure out
an easy fix I could try to repair on my own.