What can be done to fix my droopy left eye 4 days post upper eyelid surgery? (Photo)

You are just 4 days out from ptosis surgery.  This surgical result is very rough appearing. Based on the appearance, I am not at all optimistic that you will have a repair when the dust settles here.  The reason for that is that the left upper eyelid looks very much like the right upper eyelid.  I advise patience after ptosis surgery and an under corrected eyelid is better than an overcorrected one.  However, I suspect this surgery will be disappointing.  In that case, I recommend against doubling down with the same surgeon.

You are a little low still but not bad.  At 4 days the muscle will not be working at 100% yet.  So give it time and the lid should elevate. 

Ptosis surgery takes several weeks to heal, so there is no way to gauge your final result at day 4. Make sure to express your concerns to your surgeon when you go in for postop appointments.

From your photo you have much more swelling on the left lid. You are only a few days out from surgery. Be patient and over the next several weeks you should see nomalization. Discuss your concerns with your ABPS surgeon.