This is my first time posting something like this, asking for advice? So I'm sorry if I mess anything up, just tell me and I'll fix it!

Okay, I wanted advice because I don't know what to do anymore.

My whole life I've been extremely Philophobic?  
And it's completely been ruining any chance of any sort of relationship I could've had.

I don't have any close friends,
I've never been in a serious relationship,
I don't even have my own pets because I'm too scared! 

I'm too afraid that as soon as I get close to someone, or something, that I'll either mess up and ruin it, or something terrible will happen to them, or they'll just leave me, Or I'll just ruin their life by associating with them.

So I've never even tried to get too emotionally close to someone.

But, I feel so alone.
And like I'm ruining my life by wasting my best years  in solitude.

I should've made the best friends I'll ever had by now, or any for that matter.

And now I feel like it's too late.
I can't fit in any cliques now because I don't know anyone. 

And even if I truly wanted to, 
I know mentally I couldn't. 

Everytime I try I just bail out because I'm too scared to get too close.

I guess what I'm trying to ask is,

How can I make myself be less scared?

How can I get close to someone without feeling so afraid of it?

How do you guys manage feeling like this all the time?