love and choices ?

We've been together for 4 years almost 5. But idk if I should stick it out. We've had so many ups and downs . We've been together since we were 14 and now we're 18. But it's so hard sometimes. I don't deserve it sometimes and he continues to do whatever. He leaves for the marines in 10 months. I'm so confused. He's my high school sweetheart ! I need stories or anyone had to go through something like this ?