Mentally exhausted

I wish I could understand why people come into our lives with bad intention. I’ve spent the last 2 days crying, not eating, and just wondering why me. I know it’s bad to have self pity but I am to the point of exhaustion. I’m so tired of people coming into my life and telling me they love me but then doing the opposite. I’m tired of the promises I didn’t ask for being broken. I’m tired of asking for the bare minimum then being called crazy. I’m tired of begging people to show up for me when I would show up without thinking twice. I’m tired of being cheated on. I am a strong woman and I set my boundaries but somehow I still get hurt. I just can’t understand how people can hurt other people and be okay with themselves. I am so tired of hurting and getting into relationships that don’t serve me but only hurt me. Im just mentally drained