Do you think I'm a multiple?

Well, statistically speaking, you're unlikely to be one. Of course the logical thing for you to do if you think you are is to go into therapy, because whether you are a multiple or not it sounds like you have some fears and issues that you might want to explore in a professional and meaningful way.

But let me be a bit more helpful than that (although really, getting a professional involved is a good way to go). I asked the person who asked me this what make them think so. They (yes, I'm avoiding gender) said that they often found themselves wanted to do two diametrically opposed things.

And I said, welcome to the human race. For me, the problem is that often I don't want to do things - I don't experience the desire, I don't recall the doing. So I wouldn't worry. But let's assume you're not happy with that kind of answer. I would, myself, consider doing some exploration whether or not anything turned up if I couldn't remember all or most of my childhood, and if I was finding concrete proof that there were a lot of things going on in my life that I couldn't explain.