Can someone help me understand what speech disorder i have

Can someone help me understand what speech disorder i have I am really confused about what kind of speech disorder i have, so i am going to explain, would appreciate if someone can guide me about it. I use to speak really fast, but over the years i have slowed myself down, i still do sometimes when i am nervous, same is with shuttering, i shutter when i get nervous or anxious. But i really problem with my lisp, I can't seem to correctly pronoun "D", "T" and "K" sounds, its so bad that at times people listening to me wont even understand what i say and i have to repeat myself or even change the word so they can understand. I know its called lisp and based on googling i found that lisp is generally with "S" sounds. I can't much information on the sounds i have problem with. Can someone guide me about it.