Boundaries are so important! They protect your heart. This is a huge topic!
Someone who you love... What does it mean to love someone? Love is the one moral absolute, but what that looks like is fluid. So what are the guiding principles for what it means to love someone? For me, it means putting their best interest ahead of your own. That can look like "I got your back!" even if it costs me. But it also means that I am not going to let someone I love continue to sin against God or against people - including me and their propensity to continue hurting me.
That takes me to boundaries. The purpose is to show respect to self and others, and thus teach them how to treat you. In your situation you might say something like "I choose to share my life, my time and my affections with someone who keeps their word and respects my expressed needs. Because I've asked for (need) and it's just been ignored, I am choosing to end the relationship."
Then you distance yourself. You decide how much to distance yourself, and then see whether or not they start to take your needs more seriously. Boundaries are about being responsible for yourself, and to others, and that includes your feelings. If you need to end the relationship, find a way to grieve and work your way through the painful feelings the person left you with.
Of course it's much more complex than that, but it's a start.
