I have speech problems. I know this probably is not stuttering but I couldn't find anywhere else to ask this question.

I have speech problems. I know this probably is not stuttering but I couldn't find anywhere else to ask this question. Hello everybody. So, I have speech problems as I said in the title. I'm a university student who has to give presentations a lot so this is getting in my way, also people make fun of me. ​ \-I know what I wanna say, but it's like there is a barrier between my tongue and my brain, I have to pause because I just cannot say the word. It's not like stammering. For example I wanna say apple, I can't. I either end up saying a messed up version of the word or I pause for a long time. \-I cannot pronounce words correctly. ​ \-Words make my mouth and tongue feel tangled, when this happens it's hard to understand what I say. ​ \-I confuse words with other similar words. I would really appreciate your responses regarding to this. Thank you all very much, have a nice day.