Infection, allergic reaction or seroma after breast augmentation? What shall I do?

Myba,
I am so very sorry that you are experiencing difficulty after your breast enhancement surgery. Your course is not typical and the photos you shared are concerning. The bulging area on your incision line and blistering like presentation is suggestive of fluid. That can be due to seroma or worse subclinical infection. I recommend close follow up with your surgeon for further guidance. A second opinion with another surgeon is never a bad idea as well. 
Best of luck and sorry again for your concerns.

I am sorry to hear about the problem you are experiencing.  Your plastic surgeon will be your best resource when it comes to diagnosis and treatment recommendations.  Having said that, based on your history and after viewing your photographs, I would be concerned that there is underlying breast implant involvement (subclinical infection).   In other words, I would be concerned that the cause of the current incision line healing problem and ongoing drainage is that the underlying breast implant is communicating with the incision line and external ("environment").   If this does turn out to be the case, breast implant removal surgery may be indicated (to allow for healing and eventual re-augmentation). Best wishes.