Tampon problems! Please Help!!!

So my period was late for about 4 months. Then I finally got it 🙏🏻 although it was very light for the first few days (I’m not on any medication or the pill), then it became heavier after 3 days - which I thought was really weird seeming I was missing it for about 4 months. Anyway, my friend was visiting me and asked if I wanted to go to the pools and swim, I agreed, forgetting that I was on my period. But I still went, and planned on using a mini tampon for the first time 😬. So I did. (IT REALLY HURT!!!) but then my friend suggested to lubricate my vag before putting it in. She told me that it should feel somewhat comfortable and that I should be able to move around freely. Anyway, when I put it in, it slid down where my ‘cherry’ is and i struggled to stand up and bend over (move freely). but I just delt with it. Anywho, when I went to take it out after my swim, it really, really, really, really, really hurt!!! And I swear it popped my cherry or split it? And now my period is still going (it usually lasts 1 week), but it’s not bleeding heaps... just like a few drops a day, now my period has being going for 1 & a 1/2 weeks. I don’t know if it has something to do with my oldest sister who has period problems - her period lasts a few months and then leaves for the rest of the year. Last night and today I noticed that my period is brown and has heaps more discharge, meanwhile there’s no evidence of blood. So I’m not sure if it’s finished, or what is happening. Also my vag really hurts but I’m not sure if it has something to do with ripping/tearing it.