Deltoid problem please read

Hi you guys. New to this forum. I would like to ask my case if someone has encountered this or has any inputs.
I used to train alot before, few years back about 7 years ago. Did alot of steroids shot. probably about 4-5 cycles. High doses. I cant remember anymore the types that I used. Ive use oil and waterbased and about 2 times I miss injected myself and gave a really bad swelling. I hit some arteries. So to cut the story short. Ive been out of the gym for a few years since then. Been clean. from all the steroids I took before I found that my arm. (deltoids) had some cyst like lump. I thought it was maybe from too much injections that I took before. Didnt really care much about it anymore. was busy with life. The cyst didnt hurt, not until now. After 7-8 years? feels like I injected something on my arm thats making it stiff and it hurts. Feels like its sore. Its been going on since last week. for more than a week now. Im worried what it it. The cyst seemed to have gotten bigger but when I touch it, it hurts. and is so stiff. Any inputs?

stop touching it and pressing on it, you are irritating it, you likely had/have sterile abscess that got blocked off by tissue as a way to try and protect the body. hot water bottle on it or shower, with little to minimal pressure may help. but leave it alone IMO. or go to doc and mention it was from b12 shots from years ago and is now bothering you.
I am not sure how anyone takes stuff and doesnt know what they took though... anyhow thats a whole other topic.

good luck

ps, alternte sites, i DO NOT hit the same spot for atleast 2 weeks. alternate 4 spots and usually you are good. I was pining too often in delts early on and had similar issue you have.