I've been doing a good bit of squatting for since the start of the year, albeit admittedly with quite a few lengthy breaks due to a lack of self-motivation, and preoccupation with other things. I had been squatting for 3 times a week, and started off with the 5x5 program, later altering it to a 5 set x 8 rep in order to work a bit on endurance as well as pure strength, as I found that building strength alone, without much endurance was kneecapping me when lifting heavier weights. The best I got to is 5 sets x 8 reps at 100Kg, before I started to ponder on my technique, which I knew was kinda shit, but for the most part just went along with it anyways. To put it simply, I can barely break parallel without falling over, and my back is way more horizontal than it should be when squatting down. I looked into it and came to the conclusion that my ankles are restricting my mobility greatly, specifically my right ankle, which is way tighter than my left.
I looked online for some guides, and found a few exercises and stretches that are supposed to help, like the weighted dorsiflexion ERC, and another one, whose name I can't remember, but is basically putting your foot as flat as possible against a wall, and pushing your leg in, decreasing the angle between the leg and wall, and stretching the muscles that way. However, I can't seem to get them working. I tried the first exercise, and placing a weight and pushing the knee out seems to not do anything; it just forces me to lift my heel, and trying to resist that just prevents any movement or stretches. The second exercise seems to be a bit more effective, although I feel stretching in the calves, much higher than I think I should, and am unsure if I'm doing it right. Are there any better/more effective exercises/stretches that can improve ankle flexibility, am I doing it all wrong, or should I keep going with the wall stretch thing?
Pic related is the second exercise, more or less.