<human>: Give me a shortened version of the text

My boyfriend and I have been together coming up on 4 years now, and we've lived together for almost 2. 

My boyfriend and I usually get along well, but we do argue. We love each other so much, and he would do anything for me.
The bad part, I guess, is that I am just not as invested as I once was. I have had minor crushes on other people. I have not acted on these, nor have I really wanted to. To be honest, if my boyfriend and I were to break up for other reasons, I wouldn't even feel like talking to these people. I always diffuse the situation and avoid contact, but that doesn't change the fact that I spend time thinking about them.
I just find myself wanting to be alone a lot of the time.

I'm just scared because he knows me and my problems so well, and I do for him. We are *totally* there for each other. We understand what the other person needs, and we are each cognizant of it. I'm having a hard time deciphering if this is something that is unique and special in our relationship, or it can be found elsewhere. This is one aspect that I am finding very hard to comprehend letting go of. (Not to mention how cute he is).

In addition, I am fairly certain that I want to get married and have a family, but my boyfriend seems to not want this. Is it fair to factor this in at such a young age?

We are each close with each other's families, which makes this harder. 
I feel horrible about not being sure about him, but I think it's valid. I just feel like such a meanie :(
<bot>: Thinking of breaking up with boyfriend of almost 4 years but not sure it's the right move...is being this scared normal?