I feel your pain and my heart hurts for you (seriously). I can completely relate...
I was a Norwood 4 in Jan 2018 at age 48 when I had a 3900 FUE transplant with Dr Michael Vories in Charleston SC. He does exclusively FUE transplants and had more than 15 years of experience at the time I did the surgery. I was healthy, lean, exercised, ate a good diet, was on dutasteride, used hair thickening shampoo, took vitamins, zinc, biotin, etc. (not Rogaine). Even with all that I still had some shock loss, redness through 3 months, mild folliculitis, and at 5 months post-op I had a lot less growth than you see in pictures on-line. The top was the worst. Even at 8 months post-op it was still patchy, thin and bald in some spots. I talked to Dr. Vories and he said some people heal slowly and to try to be patient. I didn't take it out on him, but OMG the frustration I felt at home! It took 9-11 months to see results that other people usually get in 4-6 months. So hang in there. I know it's disheartening right now, but I really think you will see more growth over the next 6 months. Please give an update in a few months to let us know how it's going. It would be helpful to me (and probably others) to know how you are doing.
Right now I'm at 2.5 years after my first 3900 FUE transplant and I'm going for a second 1800 FUE transplant at the end of June with Dr. Angela Phipps in Raleigh NC to fill in the top (still a bit thin) and to try and make the hairline look more natural. (I have a nearly perfectly straight hairline which I think makes it obvious that I got a transplant). I am really dreading being an "ugly duckling" over the next year... crossing my fingers that maybe it will be better this time...
Thanks for sharing what's going on with you. It helps to know I'm not the only one who has had to deal with disappointing results at 5 months.