Definitely small projects! I am mostly a crocheter, but I knit (poorly) and sew (rarely). My favorite things to make are one-sitting projects, such as baby hats, doll clothes, rattles, etc.
Do you know how to do all of the crafts you have supplies for? Is it that you have been frustrated with the projects, tired of the learning curve, or just that you get bored when it's no longer "new" to you?
If it's the first, I'd definitely work on some more small stuff. That can really help you build confidence.
If the learning curve is too steep, maybe you need to focus on just one craft for a while. Get really good at that, then take on another--or decide you're happy with the one and donate/sell your remaining supplies for crafts which no longer interest you.
The third is probably the hardest, since the time we tend to invest a lot of money and time is right at the beginning of learning something new. Maybe you can find a local craft store that offers classes which allow you to pay for materials used only and borrow tools? Or you could start/join a community group that does a variety of crafts and you can share your stash with them (and maybe they'll have a stash and skills they can share with you).
Also, I've found I really go in cycles. Sometimes, I'll go months without really crafting anything, then all-of-a-sudden, I'm working on three projects at once and making gifts for everybody I know.]
Good luck getting things figured out!
