I think you already hit on the reasons why you act this way: you are treating these guys the way your Dad has treated you – “I love you but I’m keeping you at arm’s length” (or some variation of that).
Perhaps somewhere in your subconscious, you believe that this is the normal way to have a relationship, even though your conscious mind knows better.

It’s a classic paradigm that manifests itself in other much more toxic ways – e.g. if the father is abusive to the mother, the son is more likely to abuse his own wife and the daughter is more likely to allow herself to be the victim of abuse from her husband, etc. etc. etc.

And by seeking out certain types of men (older, protective, etc.), you’re attempting to replace the fatherly love and care you never received.
The good news is that in a sense, you are at least finding the right quality of man (protective rather than abusive), now it’s just a matter of taking the leap of faith to keep the relationships afloat by contributing in equal part.

Fortunately your Dad wasn’t hateful to you, but indifference is almost worse than hate sometimes in its impact on the kids.

Here’s an interesting thought – have you ever talked to your Dad about this? That may sound nearly impossible if you’ve rarely had a heart-to-heart with him about anything – having a heart-to-heart with him about why he’s never had a heart-to-heart with you is a scary thought!

At the worst, he might dismiss you and go even deeper into his shell.
At the best, he may feel willing to open up to you and explain some of what’s going on in his head.
Either way, perhaps he can shed some light that will demonstrate to you that it has NOTHING TO DO WITH YOU. Because ultimately, that is true. No matter what his reasons are, his lack of affection has absolutely nothing to do with anything you are or have done, and it’s entirely in his head. That’s a hard pill to swallow, for a child to recognize the weakness and vulnerability in our parents – they’re supposed to be perfect, right?

That’s his story.
So re-write your story.
Sometimes we have to act in a manner directly opposite of what feels right in order to do what is right.
As a previous poster said – do the hard thing. Open up in your next relationship. Love completely and freely and be completely individual. Imagine what you WANT to be like and then BE it, don’t wait for it to make itself known. You are in control of your destiny.

Good luck!