So to follow up on what you should do:
Take the advice given here for husbandry
The snake regurgitated so give it 2 weeks to acclimate and heal
You are responsible for its health and welfare now so try everything to get it used to captivity and after 2 weeks, attempt to feed it. I suggest live prey to start and worry later about weening to f/t. Also start small. The prey in the picture was too large to begin with.
After if feeds make an appointment with a vet. It is wild caught so you do not know if it has any parasites or other ailments. A full checkup is very recommend for a wild animal.
Don't give up or worry about the what ifs, focus on the now and how to best care for this animal and just provide it with the best care you can give.
Most important is be patient, don't panic, and give it time to settle in.
Oh and DO NOT handle him again during those two weeks no matter what you want to do. Leave him alone as much as you can.