Have to give a presentation at the university in-front of 50 students and professors, need advice to control my stutter.

Have to give a presentation at the university in-front of 50 students and professors, need advice to control my stutter. Started stammering/stuttering from the age of 7-8 as i recall. 22 year old male now and i have always backed out from situations like giving speeches or reading a chapter in front of the class or just introducing myself to the class/group. I cant even say my name/hometown/course without stammering. But when its always some definite letters that i get stuck and i try to avoid them as much as possible but it not always. I just hate it when i get stuck at a word and the whole class is looking at my face turned red and ready to explode. And I only stammer(a lot) when to teachers or shopkeepers or elder citizens but not so much when i m talking to my friends. I have considered visiting a therapists but thats way out of my budget and i cant afford it, just one session wont be enough and there are not so many people whom i can talk to about my condition. Have never in my life spoken in front of a crowd with more than 5 people and my upcoming presentation is making me crazy. It carries 50 marks so i cant even avoid it. Please if there's anyone who have been through such a situation or have any other advice can help I would be really grateful if you could help. Please ignore my bad grammar, english is not my mother tongue.