Failing my chemistry class I feel terrible.

I was trying to get into a vet tech program which I needed to pass chemistry this summer otherwise I wouldn’t be able to get in until January which is over six months away. I’m working and taking 3 classes and wake up at 5:30 am everyday and the chemistry class was four nights a week and my job would schedule me for the night shift and let me go 10 minutes before class which meant no time to study. I pulled an all-nighter for the last test and went to tutoring twice and studied so hard and I got a 67. I feel so stupid. I think I have to withdraw and its such a big decision and I really don’t want to do it. I’ve been crying ever since.