Will a Third Breast Implant Surgery Ruin my Breasts?

You did not state your age, but each surgery will create more scar tissue. You should be fairly sure of your decision at this point.  Take you time and think of what you want term.  Have you had kids yet?  Revision is often required .afterward

The first thing you need to figure out is what you really want. If you are still unsure, now is not the time to jump into a third surgery. Changing implants is not like trying on clothes.  Each surgery will entail a healing process and scarring. Your scar may or may not look any visibly worse than what you already have. Your skin will shrink to some degree when you downsize implants, but whether or not you need a lift at the same time depends on your skin quality and how much ptosis (or drooping) you have currently. I cannot stress enough you should get clear on what size you like before surgery (ideally before your first surgery). Have an honest discussion with your plastic surgeon of what you are looking for and why. I agree you should be happy with your breasts, but that happiness may have nothing to do with implants.

Each surgery changes the breast and with every reoperation the risk of complications increases no matter how good the surgeon is. The implants you have now are on the small side, but removing them may still require some sort of breast lift. My advice is give it more time, even another year.