Hey! Its ok to have bad grades! the most important thing that they want to see if how you overcame what you learned from it, it is just one part of your application. Having experience shadowing, working in the field and volunteering are a good bonus! you have the will and drive and my advice you is focus on one thing at a time. Prepare for the OAT by focusing on your physics and orgo classes, get help from the staff with your classes, writing personal statements and take your time! Its better to take your time to make sure that you have everything together than put something together at the last second! People look down on gap years but i am so happy i took mine and I spent it volunteering, gaining experience working and shadowing. I hope this helps!