I'm thinking of supporting a gf I stopped loving
Why do you need to be involved with someone you no longer love?
I don't see how she could live without my support.
It's okay to end relationships. You don't have to support them after that.
I can do whatever I want with my money and I will.
You have every right on how you spend your money. But I do not think that it is wise to spend it on someone that you no longer love. If you really have lost feelings for this girl, I do recommend you respectfully break up with her and if she needs financial help you can direct her with her friends and family members who will continue to have relations with her.