Permanent stitch is poking out of incision 6 weeks post op. Periareola implant with mastoplexy/donut lift. Why? (Photos)

It is very common for buried sutures to occasionally work their way to the surface prior to being dissolved.  While a nuisance, it is nothing to be concerned about.  Your incisions should heal well and look fine over the long term.

Sorry to hear that you're having problems. The number one goal at this point is to achieve healed wounds. Cosmetics will be a secondary concern and can be addressed later as they can be revised. Skin quality is an essential ingredient in the mixture that can very well determine your results. Obviously, It isn't possible to tell what your skin quality is from pictures alone. If you have very stretched skin, that represents permanently   damaged skin. In this setting, a smaller implant would be a wiser choice as it would stretch the skin less. That would be your starting point and you will continue to have that problem postoperatively. It is important that you have very limited activity in the early postoperative stages, that is, in the first six weeks. Make sure that you follow all instructions given by your surgeon. I believe that it is important that one wears a bra 24/7 for breast support postoperatively. This will minimize the tension on the incisions leading to better scars in general. Of course, follow up with the surgeon and be direct in all of your concerns.