Your baby sounds like she's really putting you through the wringer and you really need some quality rest.
At this stage I'd suggest taking help from every quarter possible and making your OH deal with the crying more, whether he struggles with it or not. As your parents are willing to help, involve them in a strategy.
At 6 months and with weaning started, she doesn't have to have access to boob 24/7. Be it day or night, have OH and your parents regularly be in charge for a few hours at a time, then start increasing the length of time. Decide which regular feeding times suit baby best and work around those.
When a high needs baby is ebf, the mum really gets a rough ride and everyone expects you to run yourself into the ground being attached to your baby constantly all day long, never able to sleep or have any time to yourself because baby needs you and only you (do I sound a bit traumatised about that
).
Actually, your baby has a number of suitable care givers who can spend time with her, love her and development a relationship with her. It's not cruel or some kind of abandonment to start taking advantage of this.
As you can probably tell, I had a high needs, ebf bottle refuser. I went back to work part time at 6 months because I absolutely needed to for my sanity. He ate food and drank water from a sippy cup when I wasn't there. It was fine. Even now at 14 months, he just wants me if I'm around, but is perfectly OK when I'm out.
We still bf 2x a day, but I'm planning to end this soon by going away for a weekend and leaving him with my parents to break the morning and evening association, then letting someone else put him to bed and get him up for the week after I get back.