I'll answer your other thread here.
Science GPA is also called BCPM, bio chem phys math. AMCAS, TMDSAS and AACOMAS count science differently, so read the fine print if you'll go TX or DO.
Here's
the AMCAS rules. Coursework info starts on page 40. Short answer: psych is under behavioral science, which isn't under BCPM.
Now, as for what BCPM courses you can take if you're running out of upper div science classes:
1. You can always retake a prereq. It doesn't erase an old bad grade (except for DO), but if you get an A it's as good an A as an A in upper div. Questionable things around retakes: doing the same less-than-A work, doing worse, too many.
2. Where's the next closest school? Can you do a summer term at a bigger university that has micro/immuno/physio/biochem/genetics/neuro/etc?
3. Be in charge of the math: nobody is counting but you. If you're doing nothing but school, sure you should take a full load, but if you can't get the classes you need, take on a job or other gig. If taking a non-science upper div class would fill out your schedule, take it and don't sweat whether one class will make or break your sci GPA.
4. Don't take lower div anything, imho, unless it's something you're really interested in. On a GPA comeback, you have to take the high road.
Best of luck to you.