TCA Cross nightmare after 4 weeks, how can I fix this? (photos)

Your skin appears to be taking its time to recover, but it is still early days and your skin will eventually recover. 4 - 6 weeks would be normal, so don't worry quite yet. It might even be longer, say 3 months as this is the time taken by the dermis to fully restructure. In the meantime use a good healing cream ideally with growth factors such as Endocare tensage concentrate to encourage healing as fast as possible. Visible red light such as Dermalux will also help the healing - it can half the healing time. Avoid the sun, smoking and use gentle products on your face until it is all healed.  

Hard to comment, but the area of skin colour changes are broader than one would expect from TCA CROSS. PIH is common, and yes, it can take up to 3 months or longer for the COLOUR changes to improve, however I think there maybe more going on. I assume your doctor is a Plastic or Dermatologist. ??? For a second opinion, one has to have the notes, and be seen in person for an evaluation. Prof. Tony Chu is the expert in UK. Hammersmith Hospital. All the best, Dr Davin S. Lim