What Causes Irregular Period And Burning While Urination?

I am on period day two and have been wearing tampons, When I take the tampon out my vaginal opening feels like it s burning and when I pee it feels like acid on a wound, I wore a pad for a whiles time and the burning seemed to not be as bad also when I use toilet parter it burns, what could this be from it has happened before but never this bad Btw my period is very irregular, I am 14 going on 15 And haven t had my period for 5 months until 2 days ago when I started. 3-5 month period gap is normal for me though