Please help, I'm really struggling 
DD had never been a great feeder. BF didn't work out despite input from multiple IBCLCs etc so we now bottle feed in the day (I pump 4 times and we feed a mix of formula and breast milk) and only direct bf at night (she's pretty inefficient and I think it's mostly comfort sucking but it helps her go back to sleep). She did have a tongue tie which was snipped at 3 weeks (private docs have confirmed she still has a little bit of a tie but that it doesn't restrict her tongue too much). She's also on a low dose of omeprazole for silent reflux. She's on mam size 2 teats.
Her bottle feeding hasn't been great for ages and only seems to get worse. The only time she'll drink more than 30 - 60ml at once is when she's half asleep. Lately she won't even feed then, but had to be so tired that she's crying before she'll eat. We're trying to sort out her naps but it's impossible when she's clearly hungry and tired but won't eat so she obviously won't nap for long, and the only way to get her to either sleep or eat seems to be to put her in her cot, wait for her to get distressed then pick her up and feed her to sleep. It seems so messed up and I feel like a thoroughly shit mum 
We have started weaning but we're doing baby led and while she loves chewing she's not really swallowing much so it doesn't really impact on milk feeding yet.
Please help 