Recurring pectoral strain/tear

Hello,

I have been trying to find a solution to my recurring pec strain/tear(left pec) for a year now. Any suggestions and insights will be appreciated. Thank you for taking the time to read.

Background: I am 22 male, 5'11 185lbs-195lbs. Been lifting for ~5 years. Bodybuilding and powerlifting specifically. Suffered a shoulder injury(left shoulder) Dec 2013, didn't see anyone for it unfortunately. I believe it was a rotator cuff tear (external rotation) and I rehabbed the rotator cuff with clear progression for ~2months. Did not bench press or do any pushing exercises within this time.

Aug 2014 - initial strain/tear during barbell bench press (no hot streaks across pec. Just felt a tear in an area of ~2-3 inches)
- Went to see a physio and was told by him "benching more than 225 will tear a pec and squatting over 225 will blow out your knees". I did not see him again. In terms of the diagnosis, he told me the pec injury was not serious and I can lift again within a week or two.

Aug 2014 to Sept 2014 - Rehabbed and had clear consistent progression. Started benching lightly at the beginning of Sept and moved up in weight slowly until i felt zero discomfort in my pec then started benching again back on program.

Sept 23, 2014 - tear again during bench press (felt hot streaks across pec this time).

Oct 2014 to Jan 2015 - Didn't see the same kind of progression doing rehab. Didn't do much in this timeframe, mainly out of fear. Very light weights would cause discomfort (pinching/cramping feeling in pec), however no un-loaded movements cause any discomfort.
- Went to the doctor and was referred to a sport's specialist. Specialist did ultrasound in his office and said he didnt see anything and was confident I should begin lifting again normally.
Jan 2015 to May 2015 - Decided to start doing incline dumbell press(15+ rep weight) and increased weight extremely slowly while watching for the same pinching/cramping discomfort. During March/April I had moved up to 8 rep weight and hadn't experienced the discomfort for awhile so I began barbell bench pressing again.
May 2015 - Pec strained again. Didnt feel any tear sensation or hot streak, but discomfort (pinching/cramping feeling in pec) was back. Went to see the sport's specialist, he repeated ultrasound but still didn't see anything.
May 2015 to Aug 2015 - Friend recommended a lifter friendly Chiro to me. The chiro performed soft tissue work on pec while slowly increasing weight on bench for ~4 months. Chiro believes that the shoulder injury(see above in "background") also included a labral tear but currently it is functional enough to not need surgery. Also believes i have bicep tendinopathy (left side) and did some tissue work there too.
- Got to 5-8 rep range weight but strained again in August. Once again didnt feel any tear sensation or hot streak, but discomfort (pinching/cramping feeling in pec) was back.

Now - Havent done much since. Been only doing light incline dumbell press. I stopped seeing chiro in Sept because it was too expensive for me (student insurance doesn't cover much) and I decided I had spent enough.

Things to notes: I bench with powerlifting technique (arched back, elbows tucked) and after the initial injury I even narrowed my grip. I have been reading about scapular instability causing pec injuries. Upon reading about this I do recall memories of my left scapula/shoulder moving while benching. Also, when I go into retraction and depression I feel stretching sensations in my left shoulder that I don't feel on my right side(not sure if previous shoulder injury is causing something with my scapular stability. The chiro would've tested for this?). The past month I have been concentrating on keeping retraction and depression while incline dumbell pressing but I don't feel its doing much.

I have attempted to make this as brief as possible so please let me know if you need any more information. Thank you.