...for a reason. When you met, there was little you would not have done for one another. What has changed?
You have. OK, you both have. Familiarity does breed contempt. If your partner isn't supporting you, they either believe you have little to offer ~ or they don't like the way you go about it.
Let your partner know that you are keen to support them ~ and ask how you can best do so. Listen to what they say and make sure you understand what they value from you. Then explain what you value from them. Explain that you are keen to have things be 'Win-Win' and ask them to tell you whenever they feel you could support them better.
Mutual support forms the backbone of any healthy relationship.