That can be really tough. A suggestion? Don't focus on the rejections or negative events. Focus on the the good things, the acceptance, the little things that go right. There's a notion called "confirmation bias." If we're scared or pessimistic, we notice the things that scare us or reinforce our pessimism, even though they may be isolated incidents.
For example, I snuck a card into my wife's suitcase with a little romantic comment. I knew she wouldn't find it for a day or two. Well, with her being gone, and me missing her so much, I was in the dumps. Then she sends me an email thanking me for the card yesterday. Made my day. One good thing in a week of crap can make a huge diff, just as one really shitty moment can ruin the best of weeks.
Keep a PMA, focus on the good things in your life, write a daily gratitude list.
