Relationship Issues

I feel so alone in my relationship bc my significant other doesn’t put in the effort that I do. I am constantly thinking about them and doing little gestures just to show them how much I deeply care about them, and end up getting nothing in return, which in turn, makes me empty inside. I know they don’t understand what they are doing is hurting me. How can I tell them without blaming them?

*currently balling, so keep the comments positive please! ily