It’s gotten worse and I’m not sure why?!

It’s gotten worse and I’m not sure why?! Currently I’m in school and I have had a stutter since I was about 8. In primary school, I only really stuttered back then when I was nervous when the teacher picked on me and stuff but now it’s gotten way worse. Two years back it sort of vanished and only occasionally appeared with other languages or in nervous situations in the classroom but recently I have been stuttering a lot with friends so much so that it takes me ages to get some words out and they just stay quiet… they know I have a stutter but I imagine it must be so painful to just wait for me to pathetically finish my sentence. At some points I dread having to introduce myself, asking any type of question in class or saying “yes,miss” in the register. Although it’s different with different people in a way? With some people it’s only there with some specific letters and appears very rarely but with others it’s hard to even say anything so my communication with them just gets cut off… and that isn’t great. I guess I’m just confused as to what this is, my parents say it’s nothing and just me being nervous and shit but why would I be nervous with friends or when I’m singing songs on my own? I do think it is a stutter though the severity of it fluctuates but I can’t really get any professional help anywhere rn, maybe when I’m older. So, to sum this up, do your stutters decrease and increase with different people? And is there anything I can do to decrease this without necessarily getting professional help..?