DS was fed expressed milk when he was smaller. He slept longer but I found this harder as I had to fully wake up, get out of bed, warm the bottle and feed.
When he eventually started breastfeeding, his sleep got worse - but I think this was actually to do with other issues like teething and his mobility - and we started co-sleeping in desperation.
Ironically I find this easier most nights and I feel more rested that if he woke just twice when he was smaller. Being able to feed, not move, not switch on lights means although awake, my body doesn't fully wake and I can usually get back to sleep within minutes and generally DS goes back to sleep fairly quickly. I am much more rested even if I actually sleep less which sounds counter intuitive.
Co-sleeping has been our saviour. DS just bounces around and screams if not held anyway, so a cuddle makes sense
I have laughed at most advice I've seen about sleep training as if its wondrous advice we'd not tried though I admit I won't even consider crying methods as I know I would never cope with them.
I do find it dreadful that there are people suggesting that giving up breastfeeding will provide a magic solution to sleep problems. I think that's misleading and is suggested a bit too readily. I think giving up breastfeeding has to be a properly informed decision made by a mother about what's best on balance. Making a decision about it in the middle of the night or after a particularly bad night because someone on the internet spouts some anecdotes is not the right time or the right reasoning.
I have good nights and bad ones. Some times I hate co-sleeping. But on the whole it works for us and I find its currently the best solution.
I am waiting it out until DS's feeding solids improves and he naturally starts to cut down on milk and is generally less reliant on it. DS feeds more during the night when he's been teething or been unwell and hasn't feed well during the day. So the logic of withholding that from him under those circumstances, is frankly beyond me. The trouble is it has been one thing after another more or less.
I think I cope with it most days because I try and take each night as it comes. If I don't I have had the odd cry about it. For the most part I figure he'll grow out of eventually.
DS slept through from 8 weeks until 4 months and did self settle. So if its parenting, then I must have suddenly changed something - which I didn't. His routine was exactly the same it was him who just changed in what he wanted and needed.