What is going on??

Hello to the community! So I need a bit of help because I don’t know what’s been going on with my body! So I am 13 and I usually have very regular periods. I am almost always menstruating 🩸  every 28 days. With 4 days of a good flowing period and the next 3 are just spotting. Lately, I have literally just been spotting for barely a full day a month. This is like bleeding a tiny bit and then no more. This happened ever since quarantine. Is there anything I can do to help my body get back and just BLEED NORMALLY? Also ok this doesn’t have much to do with periods but I’ve been feeling insecure about my boobs because I feel like they aren’t big enough. I just feel like I’m behind on that in my grade😕. Last but not least, I am 5’1 ish and I weigh now 110 pounds. I feel like I weigh too much! What do you guys think? Advice please