I'm entrepreneur whose had multiple successes and failures AND I'm a psychotherapist who works with people battling anxiety everyday.
Here's some tips (some goofy, some very practical) that have helped me HARNESS my anxiety and turn it into forward motion (instead of the paralysis you're describing).
1. Find a mentor. There are few things as reassuring as an older, wiser entrepreneur saying, "I remember that exact same thing happening to me and here's how I survived it..." A good mentor will be able to commiserate with your fears, help you break creative log jams, kick you in the pants when you need it and even make connections / introductions to help you succeed.
If you can't find a mentor, look at joining a group like Vistage in your area (I'm also in one of these and love it). They're "peer groups" for business owners and executives where we get together once a month for 3-4 hours and talk about business, life, problem-solving, etc. My Vistage group is the least lonely I feel as an entrepreneur each month.
2. Get a therapist. Really. Most entrepreneurs have backgrounds that for better or worse, have steered them towards being their own boss. Things like our families of origin, our socioeconomic status growing up, that time you got dumped at the prom, etc., all effect why and how we want to succeed and what we're afraid failure ultimately means. By talking with someone through the origins of your anxiety about failure, you'll have a better handle on what is actually driving you. Often times, we're less afraid of failing than we think. It's what comes next after we fail that we really fear.
3. Read, read, read. Constantly ingest a steady diet of magazines (everything from Fast Company to Entrepreneur to Coastal Living), newspapers (Wall Street Journal has an amazing weekend edition), to books on tape (you can get classics like "Tipping Point" for free on your phone from most local libraries). The only thing I wouldn't read are blog posts and social media of entrepreneurial experts - those often leave people feeling overwhelmed with all you're not doing or should be doing, instead of just sitting at your computer and getting the necessary aspects of your job done.
I find that holding physical books / mags in my hand and creating some space once each week to think works best for me. During my Sunday morning reading time, armed with a stack of fresh reading material I've collected throughout the week, I usually come up with an exciting idea or two that I want to apply to my businesses and that re-kindles my motivation and creativity.
4. Create a "I'm going to be successful" mixtape. Okay, I know this one is silly, but it really works for me. Music is powerful, emotive, and can affect us deeply in a short-period of time (think of how athletes listen to a song to psych themselves up before the big game).
My "I'm going to be successful mixtape" tends to be heavily geared towards rap with songs like Macklemore's "10,000 Hours" and "Make the Money," Jay-Z's "Holy Grail" and "SomewhereInAmerica" and MIA's "Paper Planes." A lot of these songs contain themes of overcoming in the face of ridiculous odds and are very comforting for me as an anxious entrepreneur. I fire this playlist up on the way into the office and I'm usually ready to conquer the world by the time I get there.
Those were just a few ideas... hope they help.
If you'd like to set up a time to chat, let me know... this is exactly the space I work in (the psychology of entrepreneurship).
Best of luck!
Coach, consultant and therapist to entrepreneurs