Triceps pain

Hello, im 29 years old overweight guy, ive been hitting the gym for 3 months and ive made a really great progress since then, two weeks ago I had a very sharp pain that i felt between the shoulder and chest when i was doing triceps pressdown.I was able to complete my sets and all of my workout routine without a single pain but after several days when i went to sleep i felt a pain on my left upper arm and since then my triceps pain from my upper arm to elbow hurts alot and its in pain,i went to doc to take a mri test for my shoulder and ill get my shoulder mri results soon but i dont know what happened to me i also feel a dull pain on my chest where pec muscle is, it hurts when i breathe.

I have no loss of strength on my injured triceps arm and i have full range of motion but its in pain 24/7 and when i try to push or pull things my tricep pain hurts even more after i done with it.

Anyone can help me to figure it out? yes i will see doc but i want to hear it out from you all too.

This is back of my arm as shown in the picture.

Jpeg — imgbb.com

Hello, stanicEnemy (unusual name).
Just to get something very clear: Pain in a certain area doesn't mean that that's where the problem lies.
I would like to know some more things before we even start a discussion. Ok?
-you say you have started to work out 3 months. Do you have had or have you any trainer, advise how to built up? How fasthave you been building up?
-what sort of activities did you do prior to the gym?
-Do you have any other symptoms e.g. numbness in hand/arm/shoulder?
-do you have any neck pain or reduced neck mobility?
-do you have any pain in the chest (you did mention something initially)? And reduced mobility of the spine (looking as far as possible over one shoulder and the other equal or one side impaired?
and so on and so on even if you think it has nothing to do with it
all the best