draconis

First let's break down the multiple problems.

1) My fiancee has just started going back to a university for school and the Army ROTC
I get the feeling after reading this as a whole this is causing you some stress and some jealously issues. What do you do, how old are you?

2) She has very controlling parents
A common problem. The major bone here is does she see them as controlling and does it bother her. If it does then she needs to show more independence or more of a back bone.
3) So what has been happening is she is swamped with school work, she has obligations to the Army
Good for her. How involved are you with her life. How supportive are you and what else can you do? I would be stressed with college work and ROTC too.
4) her parents have been telling her they dont like me.
Not a lot you can do here but show them that you are a great guy. Do something special for Thanksgiving and Christmas. Maybe even fixing them a meal or making them special guests. How long have you been engaged? Have they met your parents?
5) her mother said that if I just call and appologize, it would help
So call and give a general apology, or send a card. Better yet sit down with the father and ask him. Be sincere because you have already upset them.
6) She has now gotten very depressed and has started questioning whether she even makes me happy
Of course look at all she is juggling and she has to balance a boy friend as well?
7) She says that I am not supporting her
Be MORE involved in her life. She is facing the hardest part of her life and needs you to be there to blow off steam, and support her. This is not lipservice you need to be asking every day how was work, school, ROTC. Then you need to be making her life better. Listen to her. Be a part of her life. My wife went back to school after many years. I studied with her. Became involved so much I thought I was learning this stuff. You need to take her life seriously.
8) when i am trying everything I can to allieviate some of the stress
It appears not, don't look at it from your view but rather hers. What small piece are you missing?
9) she says she will do something and hardly ever follows through.
Maybe because of how she feels about you to her OR because she loves and trusts you so much that if she has to dump on someone she knows that you would be hurt less.
10) I see her following through for everything else and leaving me out
Jealous?
11) she is starting to get worse, having suicidal thoughts
Has she told you this? A cry for help? Maybe a wake up call?

I think you are missing big pieces here and leaving much out. Be honest this is the internet.

draconis