For the sinked in skin, which is a common side effect of steroid injections, you can get collagen filling or laser resurfacing or a plastic surgery done. There are several treatment options available for the keloid treatment like mederma (allium cepa), natural treatments like mucin from the snail helix, moist wound dressings made of silicone gel which decreases the prominence of keloid scar over sometime, steroid injections, compression bandages, cryosurgery, and radiation & laser therapy. Surgery can also be done but the recurrence rate is up to 50% and the recurrent scar which develops is actually much bigger in size. Remember that no treatment is 100% effective in the case of keloids.
You can consult your dermatologist and decide the best treatment for you.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.