How do I cope with anxiety? Every time I talk to a girl I get nervous. What should I do?
Most fears stem from the unknown or concerns about things you can't control. The best thing for anxiety is to focus on the positive things in your life. "Be anxious for nothing, but in everything by prayer and supplication, with thanksgiving, let your requests be made known to God; and the peace of God, which surpasses all understanding, will guard your hearts and minds through Christ Jesus. Finally, brethren, whatever things are true, whatever things are noble, whatever things are just, whatever things are pure, whatever things are lovely, whatever things are of good report, if there is any virtue and if there is anything praiseworthy -- meditate on these things" (Philippians 4:6-8). In other words, instead of churning over things you can't know or can't change, turn those problems over to God and focus instead on the good things you can do.
Let's use the example of talking to a girl. Most guys spend way too much time worrying that they will mess up in some way and drive the girl away. Instead, focus on enjoying the actual conversation and getting to know someone a bit better. See her as a friend, who happens to be a girl; instead of someone you have to impress.
I know this is a bit vague, but without specifics, it is hard to delve deeper into the subject.