The thing about ENFJs for me is probably how similar they are but have the ability to be more social and display excellent people skills/confidence, whereas I tend to fumble when my energy is out of whack. They're the type I wish I was, and I hold strong admiration for them (and a little jealousy).
As for dating, I don't think it's hard if you're with the right person (and really, any enjoyment in a social situation depends on the people you are with). If I'm feeling really good, I could start conversation with anyone; otherwise, it would depend on their personality and if I feel comfortable around them. I suffer from some insecurity as well and tend to push away people. I'm not even sure why this occurs, but I suspect it stems from a fear of failure/humiliation/loss. Being a sort of perfectionist, I put a lot of pressure on myself to make the best of anything, and in relationships this could be damaging because I'm focusing too hard to pleasing and not, well, relating. Like my current situation with H, I found that I'm actually sabotaging myself and instead of taking more opportunity to talk to her, I hid. And now I am at the point where I wonder if I missed my chance on actually hitting something off, if only I had been more cool and upfront.
There's a certain pressures when it comes to relationships, pressures to be in one so as to not be alone; to show that you are desirable; to show off to others; perhaps more. The first one tends to be the biggest reason why people struggle starting relationships, because they're not thinking about the relating aspect, they're trying to fill a void. On the other hand, people who take the time to develop something don't want to be friend-zoned. But I think if you can only act like a friend around someone, then that's all it will ever be. You'll know when you've met someone truly worth sharing yourself with, when it comes easy and naturally. The tricky part is finding that person.