For me, I was in a similar boat... I mesh well with many fields, none of which interest me for very long. This is my second career I'm starting up right now. The cool thing about careers is they are more fluid than people give them credit for.. You can make a foundation in a field, and take it with you to a bigger more impressive job in a slightly different field later.
I say a good start is to get a flexible degree. School gives you time to work--which is what you need. You need experience. You need to intern places, and travel, and find out where your strengths are: people skills, money, fixing things, managing problems, etc. Don't get a degree in something specific--get a general flexible degree (like biology, for example, or computer science.. something that will transfer anywhere and into any field you go into.. surprisingly nursing is a very flexible degree as well I've found) that's somewhat rooted in what you like.
Then intern like crazy. Work everywhere and do anything and everything. Also: Volunteer at places or work on school committees. Donate your time to causes and help people--and in the process, see different fields and things from all sorts of lights. Think you don't like kids? Volunteer to help out at a camp and see if you really do or not. I thought I hated kids, but turns out I like them just fine .. it was the idea of HAVING kids that terrified me, and I hate teenagers (who doesn't?). I didn't know all that time because I never just bothered to step out of my comfort zone and say, "Hey, I'm going to try this, and I'm NOT going to look for confirmation biases in the process." So work everywhere and anywhere while you get a degree. You'll keep busy and you'll have an impressive resume. You'll be moving forward while still not panicking and feeling stagnant.
After that? Just pick something. Pick something you didn't hate with good people to work for. Just work there and keep your eyes open for what you're looking for in a job. For some people that's money and a good atmosphere that's close to home. For me it was flexible schedules and something that I could work whenever I needed to but didn't need to stay steady with. It all depends on what you need.. so find out what that is, and find something that fits the bill.
Sometimes those things turn into a career. Sometimes they don't and they end up sucking and you change a couple years later. But eventually if you keep an open ear and a mindset that is not resistant to change you will find a niche you can deal with fine.
For some people careers are not what makes them their money. I know artists that work. I know inventors that operate on patients. Car racers that work at the grocery store. So a career isn't the end-all save-all of things. Sometimes a career is just, "This is what I do that finances what I need to do and actually gives me the time to do what I want to do at the same time."
