Relationship: Financial Challenges I’m Facing with My Partner

I met her in school during our master degree program and we’ve lived together for 18 months now.

We have dated for 4 years. It’s true that we’ve been having some issues in our relationship just like every other relationship out there due to some dissimilarities. But I see them not worthy enough to determine the longevity of our relationship.
Here the issue sets in, I got a job immediately after our master’s degree while she furthered for her PhD.

A city 5 hours away and as a doctoral student she is required to work as a TA to earn a stipend which is far below her bills. So, I’ve encouraged her to get another job to enable her pay her leaving expenses. But she said it won’t be easy for her to combine her TA and the proposed job.

I pay most of her bills including rent. The truth is I’m not thinking of ending the relationship because of the expenses I cover for her.  I have taken a lot into consideration and realized that we are not compatible in so many ways and pushing the relationship further will cause us more harm.
Considering the fact that she depends on me to pay at least 80% of her bills gets me more confused on how to breakup with her so she won’t get devastated.

I feel it’s bad to leave her at this stage to figure out how to survive on her own. Certainly, she’s a good person and I care about her a lot; it’s just that I don’t feel it’s right to remain in the relationship with her. I don’t want to be in relation with her any more.

I have no negative feelings towards her. And I’m thinking of how to gain her some financial independence so she can pay her rent and other expenses on her own.

So, breaking up with her won’t affect her academic carrier.

But I don’t know how to go about this, I need an honest advice please!