There are a number things which do not seem to add up in your situation. Also your photo is taken from a low perspective, so it is difficult to see what your breasts truly look like.
Given all that, I think there still a number of things worth discussing. First, nipple position is almost never exactly symmetric. If your nipples were not at the same level before surgery, they will not be after. On the other hand, your right implant appears to be higher than your left implant and it does not appear to be centered behind your nipple. Consequently your nipple appears to be rotated downwards and this would accentuate any pre-existing assymetry. Changing implant size alone will not change your nipple position.
You also stated that your left breast was too high and small after your first surgery. This sounds like it could have been due to capsular contracture which tends to produce that kind of appearance, rather that just malposition and/or implant missizing. It also appears that you surgery was done through a peri-areolar incision. This incision is associated with a higher incidence of capsular contracture which would fit with your circumstances. Also, your photo demonstrates another disadvantage of the peri-areolar incision. You have had one revision through this incision and the scar is already retracted, causing some distortion of your areola. Any additional surgery through this same incision is likely to result in further retraction and distortion of your areola, so I would avoid re-using that approach.
I do not think you have pseudoglandular ptosis. From your current photo, your left breast seems to look pretty good. The implant is lower providing more fullness and roundness to your lower breast, thus making it look bigger. Your right implant looks too high and it does not fill out the lower breast tissue, rather than the breast tissue secondarily sagging on the implant. This could be result of implant malposition, or could also be caused by capsular contracture. So your situation appears to be complicated. I think you would benefit from a second opinion. Revisionary breast surgery can become exceedingly complicated and you might consider seeking out someone with a good deal of experience in breast implant revision.