This the key: average and below average attractiveness men have to realize their target demographic is average or below average attractiveness women. There are a ton of great girls out there who don't have the looks guys go for, but are beautiful in the ways that actually matter. And since men usually ignore them, they might even appreciate the attention.
Lately it's trendy to accuse women of the 80-20 and 6-6-6 rules. But admit it, that's how men have ALWAYS operated. Get your eyes off the hotties and find someone who will appreciate you.
Maybe you're drawn to big tits, but when the right girl comes along she might not have them. If you're attracted to tall women, she may be short. Maybe you like blondes, but don't ignore the rest.
Maybe you have a long checklist of what you want, and that's fine. But unless you're on the top tier of male attractiveness, the right person for you won't check them all, or maybe even any.
Learn to be attracted to what matters, it's a hell of a lot healthier than looking for some ridiculous unattainable ideal and being alone.