My feeling is that your Release is not consistent. This assumes you are shooting on the way up, using a high percentage of the leg drive energy. Check to make sure you're doing that, too.
For the Release, you want it to be "full out" every time for all mid-range and longer jump shots and for your free throws. By that I mean, the arm extends to the end-of-the-arm at the same speed and force every time, at maybe 70-75% of maximum. Your wrist and hand are totally relaxed. The power is coming from the legs (lower and middle body) and from the pushing action of the arm, NOT from the wrist or hand. Note if you're throwing the ball or if you're pushing the ball (upward). The push can become consistent, constant.
If your Release is constant, then all you have to do get the variable power from the legs and simply vary arch to control distance. If your Release is inconsistent, that could explain your streakiness.
Work against a wall a lot, without a basket. Stand just 4-5 feet away to do this practice. (The wall needs to be clear of things, overhangs, bulletin boards, indents, etc.)
There you can observe yourself shoot without the distraction of a basket, without the "lure" to make the shot to look good. You can note how you release the ball, observe the wrist and hand. The hand will bounce or flop if the wrist is relaxed, and that's the goal. Shoot upward against the wall at a very high angle, having the ball "glance" the wall on the way down, not hit it on the way up or at the top. The latter mean you are wristing or flipping or throwing the ball. Aim high and watch how you do it. The hand will flop directly forward, toward the imaginary goal.
Start with no legs, and then slowly add the leg force, shooting higher and higher, staying in the same position. The idea is to shoot up. Observe what happens as you add leg power. Are you getting 100% of the leg power? That's the goal with most shots. You can even start to observe your "accuracy" by picking a line or a spot to shoot in line with, and see what happens. You will find the more you depend on the leg drive to power your shots, the easier it is to be accurate and consistent. Everything is very visible when you shoot against the wall. Master these simple things and shooting will get easier and easier.
When you go to a basket, keep it small at first. Find a distance where you can make high arching shots over and over with no legs (or just a tiny, consistent amount of leg drive, to "trigger" the shot). High shots, not just over the rim. Master the Release this way. Over and over. Close your eyes and train yourself. Then as you move back, start adding leg power but keep the same, constant Release. You should be able to make 80-90% of your shots, effortlessly, high arching. The leg force will vary but the Release stays the same, and you vary arch to control distance.