Congrats on your new found confidence!
From what I just read, it's sounds like you're enjoying dating and meeting people.
But...
You're acting out of fear that you will end up alone. (at least that's how it seems to me)
a lot of my friends are telling me that I shouldn't date either of them, because obviously I don't feel enough affection for either one of them to completely cut the other one off. Or they say I'm just not ready for a relationship at all. Is this true?
Maybe you're not ready for a relationship and there's nothing wrong with that. When you're ready you'll know. Our society puts so much pressure on us to settle down., get married, and start a family. Well guess what? That's not right for everyone...
Be honest with yourself and both of these women - and any others that you choose to date. They may not like it, but they'll respect you for your honesty.
Above all else - don't listen to your friends! Listen to your own heart and follow that advice. Your friends have good intentions, but it ends up being our friends who keep us from changing and growing.
Do my feelings and wishy-washy behavior mean that I should just cut it off with both? Or is it just that I have a hard time telling girls what I really want? If I do end up dating this other girl, how can I avoid putting myself in such a difficult position again?
The only thing making this situation difficult is your resistance to what you really want. Take some time to think about what you really want. Even right down what the perfect life would look like - make sure to include dating and relationships in your description.
When you're done, start living that life today - in any way that you can...