Have you talked to her and asked why she stopped putting in effort? She may have gotten super comfortable in the relationship and doesn’t feel like she needs to do anything anymore since you’re always there to do it for her, or she didn’t realize you’re not happy anymore. You sound more like a parent to their child than a boyfriend/girlfriend, so just have a conversation and hopefully things will work out. If not, be prepared to leave and find somewhere to say/kick her out