As someone who is a perfectionist and riddled with anxiety issues, I feel your pain. The thing that helps me get started is to 1. have inexpensive fabric to "waste" 2. find a small project that looks fun and that I'd like, and an optional 3. make it for someone that will be grateful just for the fact that you made it for them. Making it for someone keeps you accountable to having to DO it, and it gives you a warm fuzzy feeling when you see their face light up with happiness from having received the gift.
When I first learned to sew, back in Jr. High, we did boxer shorts, a t-shirt, and a pillow. The pillow I made was basically one quilt block, a basic 9 patch squares. So easy it hurts. It turned out a heck of a lot better than the t-shirt or boxer shorts! haha I still have it somewhere, I think. It might have gotten soaked and rotted while in storage, I'd have to look. But I still have it in my mind's eye and it was pretty.
The quilt cache someone else posted.. oh crap now I have something else to get obsessed with! Making potholders, sounds fun! That may be my next project after all the bajillion small baby projects I'm making right now.
I'm not quilting yet, well, I am making a couple tie-knotted baby quilts, but I'm making little stuffed animals and bibs and things. I have to keep telling myself a mantra of "It's for a baby, babies don't care" to get over my perfectionism. My therapist says that's a good thing to do. Someone else said it well too.. If they're looking that close, they're looking too close. or something like that. I know from personal experience, no one who truly cares for you and appreciates the gift, will ever start knitpicking it. And anyone that I've ever made something for, has had no skills whatsoever in crafting, so they wouldn't be able to spot an error even if it bit them in the nose.
Happy hunting! And get to work!