Totally understandable OP. Please don't beat yourself up about it.
You can't change how you feel, all you can do is take it one day at a time.
I went back about 6 weeks ago. I only work 2 days (long days but I'd rather condense the hours as much as possible)
I cried my eyes out the night before I went back, sat up most of the night staring at DS as he slept
In my defense I've been an LP since he was 4 months old.
I'm sure it will get easier, as everyone says "you've got it cushy, only working 2 days a week".
In truth, I hate it. Cry every evening before I go, cry all the way there and at least twice during each day.
I do it because I have to. I don't get anything out of it anymore at all.
Being a Parent makes you weird. Fact.
It will get easier OP, because it has to.