1.You are not your own worst critic. You are one of the worst, but there will always be someone who can discourage you in a much bigger way than you expected. Prepare for it, and you won't get so beat down when it happens (and it will happen.)
2. Sometimes you just need an outside party. When I say an outside party I don't mean a party that's outside :-) I mean someone who has a craft of their own, but it's not the same as your craft. Having someone who understands your need to create, but hasn't given up will re-motivate you as well and inspire you.
3. Find someone who can build a fire. My married sister is the one that lit a fire until my rear end, and it was much needed too. Find someone you look up to, and talk to them about making, selling, or whatever is standing in your way of both.
4. Just stop and think about it. Once in awhile everyone needs a new inspiration. Take a break sometimes or you'll get "burnt out" (hehe pun intended) and not want to work anymore. Sometimes slowing down, smelling the roses, and daydreaming is good for you and your shop.
5. Take your shoes off at the door. Look at your finished product as you would someone else's, with a critical eyes, and decide whether it's something that you would wear, use, buy. Do this with the prices, and every aspect of your product. When necessary you can always find your most critical, loving friend who will tell you straight up the pros and cons.