I’m so embarrassed

So I’m doing my laundry and I wanna die from embarrassment. I’m 16, and i didn’t start my period until I was 14. The past few months it’s been going haywire. It’s not regular at all and my flow has gotten way heavier. I’ve never had an issue with freshness or staining but I feel like my period and vagina stink. I’m getting way more blood clots and blood gushes. Many of my pants and underwear are stained and I hope they come out. If not I don’t know what to do with them? Throw them away?

The other issue is poop stains. I swear when I go to the bathroom I wipe until everything is clean. Then why am I getting skid marks in my underwear?

Sorry if this is gross or tmi but it’s the real truth about women’s bodies. Deal with it. I just want advice, tips, what I’m doing wrong. I do have an obgyn appointment tomorrow to address my period issue.