I think it's normal to feel a bit let down after reaching a major goal (graduating) in life. I notice I do that too.

This part concerns me though:
It scares me the fact he doesn't make me happy sometimes...
Maybe I'm misunderstanding what you mean, but it's not his job to make you happy. That's your responsibility. And nobody is happy all the time. That's just life.

Getting away might be just what you need. Focus on yourself. Things that you can do to make yourself happy.

Keep plugging away at getting a job. It's hard out there right now and rejection always brings a person down. But, you'll feel better about yourself when you're working and then the little things won't seem like such big things.