Can this be considered using my bf?

I have been debating breaking up with my boyfriend for the past few weeks. We have been together for almost four years and are both 22. Sometimes I go through periods where I cannot imagine any life that does not involve him, but some days I feel like we are just too different. When I go back and forth on whether to break up with him or not one of the big things that comes to my mind is that I am worried that if I leave him I may fall into a routine of partying and start to become irresponsible. I am majoring in criminal justice so this kind of lifestyle would be a very bad career decision.
I think that I am mainly worried because when I left him two years ago that is exactly what happened. I feel like this may almost be a form of using my boyfriend. I wonder if this is the case. I also wonder if I feel like this because I am scared of being alone (i have not been single since I began dating) and feel like the guy that I would be with would dictate my lifestyle.

Is this considered using him? And if I feel like this should I leave him? I mainly have been thinking of leaving him because he can be really immature around his friends and I also cannot stand how much he hates everyone as soon as he meets them.

I am really confused on whether I should stay with him and keep this going or if these feelings are a sign that I need to move on.

yea you are using him
its unhealthy to base your life off people. you should be single for a while so you can figure out how to live your life without depending on someone.
you will get lonely, but its not the end of the world. when you stop being lonely even though you're single, thats when you should start dating again.
its not fair on him for you to feel that way about him but still be with him.

Look at it this way. Couples should primarily act like pillars, not a crutch for the other.