I can’t sleep HELP!

Kat

Baby girl has done pretty well the last few nights but the problem is me. I can’t relax and go to sleep. My mind and heart race over checklists- will I forget something tomorrow (I’m back to work). Will I sleep through her crying in her crib? I sleep maybe 3-4 hours a night and I can’t do it anymore especially when school starts. Is it ok to breastfeed and take melatonin? Is there anything to help sleep?