Regarding the "Crush" discussion, as someone who has dealt with anxiety and social anxiety my entire life, the phrase "I've never met her, and I already know there's no chance" is a familiar one, so you're not alone, but it needs more evaluation. You justify the crush, as well as the emotions behind it, based on a physical attraction and maybe some conversations you've overheard that person having with other people that hint at their character. However, if you've never met them, you don't truly know much at all about their personality or interests, and are largely idealizing who they are based on very little information. Letting your mind wander about how fantastic the world would be if you could just have someone like that crush in your life, then approaching them from a place of desperate need and insecurity is selfish and counter-productive.
We live in a world that is growing increasingly shallow, with Tinder, Twitter, and Instagram reducing our evaluations of other people down to bathroom selfies and 140 character or less stream-of-consciousness regurgitations. Look at any female OKCupid profile and at the bottom it will probably say "You should message me if......you have something to say other than 'Hi, ur pretty'". If the person you have a crush on is single, seems to have their life relatively together, and is intelligent as well as attractive, walking up to them and saying "I know you aren't interested, but if you ever are..." when you already have the negative self-worth running through your head, is the same as telling her "I don't think much of myself, so you shouldn't either." Telling someone they are attractive, then sheepishly walking away will be just as awkward.
I'm not saying this to be harsh, but so that you consider re-evaluating your motives and self-worth. I wholly believe people should be more free with sincere compliments and positivity. If you were confident about your value on this earth, your intelligence, and accepted that you are who you were meant to be, you could walk up to anyone (regardless of whether they were 'Out of your league" by some arbitrary social standard) and say something like "You look nice today. You always seem to be smiling, what's your secret?" Something more than surface flattery, but short of waxing poetic and telling her she shines like a golden flower in a sea of drab, lol. If she responds and leads into conversation, great, if not, it didn't cost you anything to be nice.
Compliments shouldn't be so tricky to give out, but they can be, especially compounded by anxiety. I remember back in my first year of college, I was in a lecture hall of 200 people, and as it filled up an amazingly attractive girl who smelled sweetly of perfume sat right next to me. My mind told me to tell her she smelled nice, but what actually came out of my mouth was "Is that Sunflower you're wearing?" to which she replied "No, it's (insert random perfume name here)", and then in an inexplicable, slow-motion moment that I still don't understand to this day, my panic-stricken mouth spit out "Oh, some perfumes play with my allergies, I was just curious."
I didn't even have allergies!!! Why did I say that?!
"Oh, I'll try to remember not to sit by you again, then."
But back to my point, the reason that people say that you'll meet someone when you least expect it, when you're out pursuing your own interests, isn't because the world is random and you need to go swim in the sea to find the fish, but because when you're pursuing your own passions, other people will see it in you. It may take time, and it won't save you from spending some occasions alone muttering about those around you who seem to have everything handed to them, but you have to find yourself before you can share that with anyone else.
Best of luck.
Flogg - Tauren Resto Shaman
Arygos - US