I can assure you that OP is far from inexperienced, as a guy who knows stig personally and even went in field with him, this guy is legit
What happens is when a girl shows high IL it can really throw you off when she is not congruent
His situation sounds similar to mine except we went on 3 dates, she paid for 2 of those dates, and showed super high interest. (3rd one at my place where she blew me) was suppose to go on a 4th date and she said she was "sick" I have not heard from her again.
I do agree that women are very fickle when a girl can blowy you on Thursday and on Sunday act like a completely different person
Heartise while I may not agree with some of his stuff I do think being "Indifferent" is key here, this is why spinning plates is so important. It literally combats thrist, needy behavior etc.
Personally stig, I wouldn't reach out but that's just me, if you do reach out, do it once and see if she response and act accordingly