I Really Need Some Help and Advice...Please?

I feel a mental breakdown coming on, but I need help with a problem beforehand...how the hell am I supposed to put walls back up when I'm around someone I don't want to have those walls up around...

That probably doesn't make much sense, so I'll try again sorry...

Ever since I started liking him again he's slowly been knocking down all the walls I've spent years putting up, and I liked him doing so. But now, I've got to put them back up, I've got to try distance myself from him, because I'm getting hurt already for being in too deep. He doesn't care, he never has and probably never will, and I'm starting to see that, but like I said, it's hurting already, so I wanna start putting some back up before he tells me those facts himself, so maybe it won't hurt quite so much.

So anyone got the answer, how do you put walls back up round someone you don't want them up around?

Breakdown time now, but thanks to anyone that can maybe possibly help, or is willing to try!

This song is pretty much spot on...

When You’re Gone
Will I lose control?
You’re the only road I know
You show me where to go
Who will drive my soul?

Drive My Soul by Lights

Damn good for New Moon too...