Bad shoulder pain since july, what can i do?

Hi guys, so this is my short story: after 8 years of full stop from working out, almost a year ago i've started again with crossfit (actually a variation without barebell). i had no problems at all, but since july i started having a pain in my right shoulder. the pain stays h24, even during night i have trouble to change side in the bed. i use a lower weight when there are shoulder workout, but still nothing. i did some cortisone therapy, but without success. i don't know what it could be, when it hurts a lot i have pain even when i took my shirt off. based from your experience what could it be e and what can i do?

plus, do i have to apply ice or warm on it? until now i've applied a warm medical-gel from time to time in the evening when i lie on the bed, but i don't know if i should use ice instead