So you have weepy, angsty one-itis for a bratty BBW woman, and are rationalizing it every whichway all over this thread. You have got to start doing some things differently. Just look at all the time and worry you have spent typing and thinking about this one low quality woman who is still almost a total stranger.
1. OLD, as others say pay sites are better. Contact as many women as it takes to get 3-4 dates. Go out with all of them. See what sticks if anything. If something does, keep dating others. You are still dealing with unknown quantities, almost total strangers. Don't assume they are all quality just because you would f them, most of them aren't. Get out that gold mining pan and sift that sand out. You are a miner with a long term plan, not a sucker who latches onto the first fool's gold nugget he finds.
2. One falls out or flakes? You have to put another one in, right there, right then. Keep 3-4 in your pan/bucket at all times. When one drops out, find another, be robotic and consistent in this. It is key to preventing what has happened to you. Don't just do OLD, start finding places to meet women in other ways, OLD is just one tool, not the whole belt. Get involved in local charities, animal shelters, conservation, whatever you like, go to their fundraising events, meet women. Separate your party time from woman meeting and number getting time. Don't go out looking for women, then get discouraged and drunk. Go out with a plan to work several familiar places, stay sober, go home early. Rinse repeat.
3. Keep your dating binary. Keep asking them out as long as both are true: a) they are enthusiastically accepting your date invitations; b) they are enthusiastically accepting your escalating physical advances. If you take nothing else from this post, take the following, everything else, and I mean EVERYTHING is noise. What they say, who they say they are with, interested in, all of it... noise to be discounted. Keep your dating binary, keep yourself sane. Once a or b cease to be true, give one more invitation then move on instantly and get another prospect in that bucket.
4. Keep contact to a bare minimum early on. Call and ask out, keep all your talk for dates. No texts, phone, IM, nada, other than to ask out early on. Keep things light and flirty in person, never deep, heavy. No movie dates, sitting across a table, do active things, sit next to each other at the bar. Don't be like a dog trying to get invited over to sit on their couch and lap at their toes. Have a fun date plan; make the move for sex at the end in a matter of fact way, "hey want to head to my place?" Do that two=three times and if they aren't at least getting really physical with you by that time, even if not quite sex yet, then out for good and find another option for the bucket. Use any angst or worried rejection time and feelings to fuel your desire to get the bucket back full, to get back to your gold mining plan, not to sit around and ponder why one particular one blew you off.
5. Women can smell a man with options, a man of plenty. Have options or be the prey of every privileged bratty BBW you meet, choice is yours. Follow my instructions and in time, you won't ever be dating such low quality crabs any more, not even once.
Don't take the above harshly, but bluntly. I didn't have anyone to help me way way back when I was making the mistakes you are making, and wish someone had given me the straight dope without any sugarcoating. Good luck.