Irregular Periods

I used to get my period at the beginning of every month, that remained consistent for pretty much my entire experience with my period. I got my period in 6th grade i am now a Junior in hs so 5 years. Recently at the beginning of 2020 i started to face irregular periods. It was so irregular that I didn’t have my period between April all the way until October. I didn’t have my period at all in between then. after October i sims they it November or December and i JUST got it on the 22nd of January and my flow is extremely heavy. I have to change my pad every hour because if i leave it on for more than that i will soak through my underwear and my pants instantly. I’m extremely concerned because this isn’t normal i’ve only had a period like this once in April. Also, there’s no way i was pregnant I am a virgin. Not to mention I have the worst cramps possible. I cant take any pain medication more than once because it never works after the first time. The cramps are so bad that all i can do is cry and sleep. I cant eat, I have absolutely no appetite, which is normal, but it sucks. And it’s only day 3 this can last up to two weeks. I’m very miserable and idk what to do. I also cannot use tampons because they increase my cramps by a 1000. Someone help me, idk what but I need some kind of guidance this is horrible.