Maybe contact your school counselor and talk about the specific problems you're facing with motivation, they may let you have extensions or even extra support classes if you voice your struggles. And don't worry! We're all struggling with studying/grades during this pandemic :( you're not alone
A 3 isn't the best grade ever but to pass IBDP you'll need at least a total of 9 points on your SL subjects and 12 on your HL subjects, so as long as you meet that threshold (and a few others) you'll pass.
Also, I found this website that has videos on every topic in SL and HL Chem for DP: h