Anyone done speech therapy as an adult?

I'm 18, no one said anything about my speech and the way I talked when I was younger but now at 18, working and college I notice. I work as a shift supervisor and it's so embarrassing when I slip up while having a professional conversation. Talking in class, talking to my teacher ect. I can't pronounce "th" words, the letters r and s and many random words. It's embarrassing. Anyway people who have done it, what was your experience? Did it help? Please and thank you