Forearm injury- what's wrong with it?

About two years ago, I was on a training exercise during the summer. I was carrying a 10-15lbs object like in the photo attached.

My arm gave out, but I decided to press on and carry it all the way to my destination.

I thought it I had just over used my muscles a bit, however, the next day, I felt like, how to put it, an electric surge going from my palm up to my elbow. Included in picture.

Throughout my training exercise, I did the the normal pushups, chin ups, digging and whatnot, thinking I had just a sore muscle in my forearm that needed to rest. Then the random, intense pains began during the day. Similar like the electrical surge feeling, but it was painful and lasted up to a minute. The other pain experienced was when I would wake up in the morning, again, from the palm to the shoulder, I was in pain. In even more pain than during the day.

When I finally got home, the next morning, I wasn't able to close my hand at all. So I slapped a brace on it and gave it a week and it was a bit better. Fast forward today, and I still have this discomfort in my forearm and thumb, it feels sore, and the only relief I get is when I stretch my hand and try to crack my wrist/thumb.

My finger tips are cold and the only kind of pain I get is when I press down with my thumb. I also hear some sort of grinding, when I rotate my hand.

I have seen chiropractors/osteopaths/family doctors to try and help me find out what's wrong and they all keep telling me the same crap: stretching. I've stretched and massaged and taken ibuprofen and it doesn't seem to help.

I can't afford to see a physiotherapist until my income tax comes in so I pray that you would kindly tell me your opinion on what's wrong with me so that way I can get started on it and get back on life.

Thank you!

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