I need help with my stutter(?)

I need help with my stutter(?) Now, the reason i put question mark in the title is it is a little complicated. I just graduated High School and i have an ongoing problem about this. I speak too fast, i swallow syllables and sometimes stutter when i try to slow myself. This generally happens in regular chatting. And this doesn't happen when i am giving a speech or saying something important to a superior. And I should add I couldn't make the sound "R" when i was a child. (idk if this is related) this might not count as stuttering but i had nowhere else to go. (If you know the place you can direct me to there too)