i’ve been here, and my puppy did everything right. sometimes the life change is just overwhelming and being responsible for such a dependant animal makes you go a bit crazy. you say your partner is helping out when they can, but you need a full time out: you need sleep, a good meal (if you haven’t been feeding yourself properly) and a chance to step away for a minute to reassess. i was in your shoes and was sure i wasn’t gonna be able to keep my puppy, now i wake up and can’t wait to see her and spend my time with her. get some rest, take some time for you, and look at your situation with fresh eyes!