A ff needs roughly 2.5 floz per pound in weight in 24 hours so she should be having around 17 floz, is she getting this?
You don’t say if the HCPs have said if the jaundice has cleared, if you’re not sure, I’d take her to the Baby Weigh-in clinic this week and discuss it with your HV.
Also, are you waking her every 4 hours at night or do you mean you are having to wake her every 4 hours in the day too?
If you are having to wake her in the day for a feed, I’d try after 3 hours from the beginning of the last feed. Change her nappy, then try feeding her. I’d try burping her at least once during the feed too.
Could you try something like this, assuming she’ll take 3floz, but offering 4?
Feed at 7am, 10am, 1pm, 4pm, 7pm and 10 pm and then if she wakes for it at any time in the night. Otherwise, assuming the jaundice has gone, I’d let her sleep.
I know that babies, including ff babies should be fed on demand but with a baby who’s very sleepy. I’d be waking them.
I’d also get her outside at least twice a day. Could your DH get up a little earlier and wake her around the garden in the morning while it’s so light and nice? This will help her circadian rhythms and will give you a break to get a shower, or some much needed sleep 
And you are not a crap parent. You don’t need to justify why you are ffing to anyone. If you’re really not sure what you are doing, UNICEF have produced a leaflet on Bottle Feeding and you’ve always got us MNers here for you 24/7 