Capsular contraction, big gap between the breasts, and maybe bottoming out? (Photo)

Thank you for the question and pictures. Unfortunately, online consultants will not be able to provide you with specific enough advice to be truly helpful.  It is possible, however that you will benefit from revisionary breast surgery that will likely include maneuvers such as adjustment of the breast implant capsules (capsulorraphy),  the use of acellular dermal matrix if capsular contracture is present, and/or adjustment of the breast implant size/profiles. Generally speaking, the best online advice I can give to ladies who are considering  revisionary breast augmentation surgery (regarding breast implant size/profile selection) is:
1. Concentrate on choosing your plastic surgeon carefully.  Concentrate on appropriate training, certification, and the ability of the plastic surgeon to achieve the results you are looking for. Ask to see lots of examples of his/her work.
2. Have a full discussion and communication regarding your desired goals  with your plastic surgeon. This communication will be critical in determining  breast implant size/type/profile will most likely help achieve your goals. 
In my practice, the use of photographs of “goal” pictures (and breasts that are too big or too small) is very helpful. I have found that the use of words such as  “natural” or "C or D cup" etc means different things to different people and therefore prove unhelpful.
 Also, as you know, cup size varies depending on him who makes the bra; therefore, discussing desired cup  size may also be inaccurate.
3.  Once you feel you have communicated your goals clearly,   allow your plastic surgeon to use his/her years of experience/judgment to choose the breast implant size/profile that will best meet your goals.  Again, in my practice, this decision is usually made during surgery (after the use of temporary sizers assessed with you in the upright position).
I hope this (and the attached link, devoted to revisionary breast surgery) helps.

Surgery is the only effective remedy. Revision surgery is almost always more complex than breast augmentation. Correction techniques vary based on your plastic surgeon’s experience and skill sets. Always choose a board certified plastic surgeon with expensive revision experience as even in the best of hands recurrence is frequent especially if larger implants are used. Repair techniques include some of the following techniques and recommendations:Textured implants (“Velcro effect”)Use of Smaller ImplantsMaximum Submuscular Position (not just the pectoralis major but abdominis rectus below and serratus anterior on the side)Capsulorrhaphy (tightening the pocket by sewing in-folded capsular tissue together)Use of Biologic fabrics and other materials such as Acellular Dermal Matrix, “ADM” Alloderm, Strattice, “Silk” and others that can be used to reinforce the bottom of the pocket.Change of position of implant to a new pocket location “neo pectoral pocket”Internal Ryan Procedure (sutures binding the inferior mammary fold to stronger underlying tissues (e.g. fascial, periosteal)Removal of Implants and replacement of volume using your own fat (Fat Transfer).The procedure is performed under general anesthesia on an outpatient basis most often using an existing scar or making an incision beneath the breast. Recovery is similar to your original breast augmentation procedure. Use of taping after surgery and prolonged use of a support bra is often recommended. It is far more important to pick the best plastic surgeon rather than trying to pick the best procedure as they are in the best position to guide you to the right decision.

Thank you for the question and photos. I believe that a complete revision is necessary. Your size looks good so you have a few options. You could continue with round high profile implants or switch to a highly projected tall height shaped silicone gel implant which will maintain a full and nicely shaped upper pole and similar breast projection. I would recommend also the use of a dermal graft in the lower pole for support and capsular contracture prevention. You are young and thin and revisions are expensive so I recommend going for the most reliable single procedure. Discuss this with your board certified Plastic surgeon. In the implant revision section of my before and after photos there is a similar case, at drmouchantat.com.