How to Treat Medial Collateral Ligament Pain

Hello,
I have been experiencing pain on the inside of my left knee for some time now and would like to know what kind of treatments would be best for it.

The pain is a 'burning' sensation, isolated to a small area across the joint of my left knee, beginning almost on the inner knee joint (slightly to the rear) and stretching approx to the beginning of the rise of the knee cap on the inner left knee. So, it's probably an area of about 3 inches, from joint to knee cap-base, and approx 1 to 2 inches deep.

As such, I have (myself) determined that it is most likely the medial collateral ligament.

IT was caused, originally, during some squats I was doing in the gym. I remember feeling a kind of 'twanging' on that exact area as I did some squats -- as if an elastic band was rubbing across the knee joint as I went up and down. Although I didn't feel any pain at the time and stopped the squat session soon after I noticed the sensation. The pain afterwards didn't come on quickly soon after, it just sort of began and I got used to it before I realised it wasn't going away.

As an 'injury' it is simply a pain. Although a very sharp one that is sharp enough to prohibit activity when it occurs. It's like a burning pain.
But the injury doesn't inhibit my movement in any way. I have not noticed any instability with that knee, for example.
It's the 'pain' that is the problem.

I currently wear an elasticated knee brace when I am going out, because walking tends to aggravate it, and that knee brace tends to 'work' (EG I can walk for relatively long distances without causing pain).

I have tried a variety of 'low impact' exercises to try and do whatever repair or strengthening is required to rid my knee of this recurring pain, but even when I think I might have hit on the right combination of exercises, it will return with a vengeance and I'm back to the beginning again.

Walking and normal squats tend to aggravate it. Knee extensions or hamstring curl-style activities don't seem to aggravate it, but don't seem to improve it much, either.
Just before the virus closed the gyms down, I found something called a 'sissy squat' machine (a metal frame, really) which allowed me to do squats without aggravating that knee, which I thought might be an exercise I could do to build some strength around that knee to support the joint better, but then the gym closed.

For a while I was surprised to be waking up in the mornings with the pain, until I realised that by lying on my right side, my left leg (and therefore left knee) were probably bending against that ligament in the night, and aggravating it -- so I know sleep with a large cushion between my legs.

Anyway, that's about all the detail I can think of that might be relevant. And probably too much!

I'd just like to understand a little more about the problem, what is the typical remedy and procedure for repairing it, exercises, etc.
Thank you!