the funny thing is, i think OP lowkey kinda liked her in that way.
i think she was attracted to him but mainly wanted attention and affection without committing to him. i think he originally wanted sex but after spending lots of time with her (4 meets), when she said the relationship thing he was taken by surprise cause he wasn't expecting that (cause he words and behavior didn't match so far) but actually considered it. and maybe she wasn't expecting him to say he was considering it, or maybe she interpreted it as a rejection (i personally didn't see it that way when i read the OP). whole lots of mis-communication. But OP will learn and overall, i think while a little clumsy (as we all can be from time to time), he did the right thing if he was true to himself.