Wrist tendonitis and outcome

hello, this is the first time i am posting here so I apologize if I'm doing smth wrong...

For 2 months now I've been having pain in my right wrist. It started with just small pain next to my wrist bone (on the upper side) only when I stretch it (move in circle). Being stupid, I stretched it too much and ignored the pain and it hurt more (it was not unbearable, from 1 - 10, around 3 and only on certain movements). I went to see the doctor twice, both times he gave me a gel to apply and said the diagnosis was tendonitis or tendovaginitis. 10 days ago I was typing (I work on the computer a lot) and as I stretched my pinky to reach the Enter, the pain got worse, around 4-5, I felt like my wrist is hot. Went to see the orthopedist again, he put my hand into cast splint. While immobilized, it still hurt, it was hot from time to time. Today the doctor took away the splint, gave me a gel, told me to use salty baths and if the pain doesn't go away for some time, he will have to give me an injection into my wrist...

I am so scared. My wrist was immobilized for so long, but it still hurts. I can't play the guitar, I can't ride my bike, I can't do anything, I am typing with just left hand... I don't want that controversial way of treating this (injection). I just want my hand back. Are there any ways I can help my self. Will the salty water help? Please, please, give me a piece of advice..