My body won't let me progressively overload

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I've been working out for 4 years now. At first, I was just doing push-ups. I would do 10 sets of 10 reps (which was my max then) all throughout the day and be done with it. But once I learned more about working out and developed an actual good routine, I changed to a normal 4 sets of 12, along with other exercises for the rest of my body.

(I'll be using push-ups as a metric here mainly because that's my struggle)

Now fast forward to today, and my maximum all-time number is 32 in a set past failure. Right now, my point of failure is around 25 or 15 if my body's just not feeling it for whatever reason, and it's been like that for the past 2 years.

I just can't seem to break out of that range at all. And even if I have days where I do push myself forcefully past that point (which is how I got to 32 in a set), it always reverts back to normal the next session. As expected, I have not gained any more muscle these past 2 years in my upper body because of this. And as for my legs, well, they won't visibly grow no matter what I do.

Since I've lost access to my weights, I've had to do bodyweight squats. Now I do around 50 a set for like 3 sets, then add jump squats simply to focus on explosive muscles since the mass is not growing.

Any tips?