I seriously can't pronounce anything!?

Okay so I have always had a speech impediment with words that have 'R' in it. I still have it (I am 14) and it won't go away. I was in a speech class from Kindergarten to 6th grade, to fix it. To me all of my words sound fine, but to other people I sound all weird and almost none of my words come out properly. I recorded myself talking regularly and listening to myself it's hard to understand what I am saying. Also my voice is kind of high pitched but not to myself. Whenever I talk to people in games and stuff they think I have an accent or something, then one of my friends points out that I can't pronounce words properly. I really don't know how I fix this, it's not only with R's, it's with almost all words. Thanks!