Relationship Advice

Guys, I need your advice.

Me and my girlfriend have been together 3 years.

She looks after me very well as regards to feeding me, buying me things, etc.

Now when she is feeling down, or sad, or whatever, I will stay awake with her hour after hour after hour until she falls asleep feeling better. Even at the loss of sleep for my own self.

When I need her, She hardly ever stays up with me. Says she is tired from school, etc. Where is my help? If she has caused an issue or caused me to feel anxious, depressed, sad, she will not apologise whatsoever. She'll just fall asleep and leave me to lose sleep over all mine/hers/our problems.

She tells me what to do as regards to work (what jobs to go for etc) my personal and social life, family life, the list goes on.

FYI I have tried talking about this with her but it's like talking to a brick wall. I'm 18 and she is 16.

Help me, I'm so fed up of not being allowed my own way sometimes. Pathetic, I know.