Multiple digital(?) Problems Regarding Both Analogue Sticks

This all started seemingly randomly about a year ago and has gotten worse over time.

1. This seems to be a fairly common problem: when I hold L2 it also register as the left analogue stick being pushed forwards. The more I hold the L2 button the more it registers the left stick being pushed forwards. Holding L2 down 100% also registers as the left stick going forward at around 80%.

2. Interestingly it seems that at the same time the left stick lost that 80% of control over moving forwards. Although physically nothing seems wrong, moving the left stick forward registers nothing until it reaches 90 or 100% . So, the only way to move forwards with the left stick is holding it up as far as possible.

3. Lastly but arguably the worst, moving the right analogue stick to the right also registers it as being pushed downwards so when trying to go absolutely right it registers as going 100% right and 100% down. Same thing happens when pushing it to the left but instead of also registering downward movement it registers upwards movement along with the leftward movement.