Be confident but realistic. Don't only punch above your weight
If a girl rejects you, don't take it to mean all women are bitches. They're not, and thinking that makes you a douche
Don't think that because a civilian girl won't do Greek or won't let you CIM, she's a bitch or sexually repressed. Realize that the entire SP thing is a fantasy, and only that. Not a substitute for relationships or social interaction. Sex is a very important part, but it is only one part. Not every girl wants to fuck 24/7. I guarantee, that at least half the guys on here who are married or in a relationship, and who say that sex (or lack of it) is the biggest reason they hobby, are lying either to themselves or to us. Sex may be a reason, but there's deeper issues with their relationship that explains why they hobby
Getting rejected is not the end of the world. Everyone gets rejected
Know your strengths, work on your weaknesses.
Bars/clubs are not the only, best or even good places to meet women. Know that only a select proportion of guys can pull this off, and even then they get rejected far more than they succeed.
As fuji says, getting yourself out there and involved with as many social groups and clubs as possible is a great way to meet people. After college/university, the sheer number of people you meet goes way down, and your social circles drops off. Especially when your friends get into marriages and start having kids, your social circle can shrink. You need to widen it.
Don't listen to bitter people on here spouting statistics about fucking suicide rates in Australia or genetic theory, or how women only want 6'1 white guys with 200k a year income. There's someone for everyone out there, I truly believe, and if you haven't found it, it's because you haven't put yourself in a position to find them.
Don't be desperate. Be comfortable with your life. As fuji says, if you work on your weaknesses (your gut, your wardrobe), you'll feel better about yourself. This will translate.
View the hobby as something completely separate from your social and dating life. There's no crossover. The only possible advantage is that you might be a little comfortable with sex. Other than that, there's no resemblance between the two. If you really need to scratch the itch, then do it by all means, but try and increase the times you take the 250 and invest in taking a class or a new piece of wardrobe or something else other than hobbying.
If you truly are extremely socially awkward, or have some kind of disorder, do not ask a SP for help. They genuinely may try and help, but remember they're being paid, and it's in their best interests professionally, and even from a safety point of view , to be as gentle as possible and tell you only what you want to hear. This can lead to disastrous consequences in the real world. SPs, at least good SPs, do become pretty good therapists in their own way, but they're not trained. This seems silly, but if you truly have no else to talk to, and a severe personality disorder, looking for a SP to help you can easily fuck you up worse than you were before. A therapist is the best bet. I truly think many guys would do themselves, and their families and friends, not to mention the SPs they see, a better service by investing hobbying money into therapy. Therapy isn't a cure-all obviously, but it can help tremendously.
Life is far too short to spend it bitter. Bitterness eats away and like Yoda says, can lead to the dark side. Don't be bitter