@Bex5490
It's not a guilt trip, it is scary for a little one to be left without their main carer giver and not know why, she needed to be prepared before hand, she didn't have to mention who she was going with just "mummy is going to the cinema to see a grown up film and then for something to eat afterwards, mummy will be back tonight and we will have breakfast together. While I'm not here grandma will look after you" etc. it's the not mentioning it that is the issue.
If OP needed to swap to evening shifts then presumably she would warn her child, "mummy is going to work, I will see you in the morning". She wouldn't go off without a word.
I know single parent hood can be hard and lonely, I've been one for 15 years and sacrifices need to be made. Dating costs money, time and emotional energy, OP if living with her mother, needs to spend that time, money and emotional energy on getting herself independent and in her own place to give her and DD the space they need. There is a time for dating but now isn't it really until the basics are covered.
If OP wants to carry on dating then she needs to rebuild DDs trust that she'll always come back, that's the only way to help her through this screaming phase. So lots of going out and coming back when she says she will. Little ones don't have concept of time so you need events, I'm going out but will be back for lunch / bedtime / before Bluey is over or whatever.