Exactly.
I've been there recently. It's hard to put yourself out there, especially when you aren't confident in yourself.
If you aren't optimistic about your chances on a dating site then work on yourself for a little while. Take one hour, ever day, and go to the gym or go for a walk with your dog. That's ONE hour long TV show that you just have to skip. One show a day that you can do without.
Even if the results are drastic, you will feel better because you are DOING something about it.
I was single after 9 years of marriage and I had no clue what to do. I had no self confidence and I was depressed as crap. I started focusing on me, instead of worrying about my ex, and I felt better eventually.
Hang out with your friends more. I was somewhat alienated from my friends after my first marriage. I started hanging out with my friends more and I remembered how it felt to be myself. I'm a funny, happy guy. I had a blast tailgating and catching up with everyone. And if you're lucky, your friends wives might have someone they'd like you to meet.
But first you have to like yourself before anyone else can like you.