Kettlebell Injury - Tendonitis Maybe?

Hi, y'all. This is my first post in the forum, so I hope I'm doing it correctly.

So I really dove into full-time kettlebell training months ago. Father of 3 kids under 3, no time to work out anywhere but home. Y'all get the gist. Back in November, I decided to do some heavier (40kg) single-arm kettlebell swings. I shouldn't have done that because I simply wasn't ready for it. I felt a pop in between my forearm and bicep on my left arm. The pain lasted a few days and then largely subsided. But every time I go heavy now, the pain returns. I've been putting up with the pain for months now. Even had it looked at via ultrasound and X-Ray on separate occasions. Now the doctor wants to do an MRI.

The pulling exercises are the absolute worst. Last week I did 56kg single-arm rows, and I haven't worked out since because of the pain. And now the pain has crept up into my shoulder and trap area on the left side.

To be clear, I can still work out. But if I'm doing something like cleans or strict press w/ 32kg or 40 kg, the first couple of sets are incredibly painful. Then it gets a little better after that.

Has anyone else dealt with this? Could it be bicep tendonitis? Just looking for some answers. Thanks for anything y'all can offer.