rickman exactly the same thing happened with myDS3! Having seemed mad keen on solids at first he then wasn't interested in them for a few weeks.
Has he been unwell? My DS3 was quite under the weather for a while and was also very whingey. I know what you mean about feeding all night - this is exactly what DS3 was doing.
My advice fwiw is leave it a few weeks and then try again on solids. And then don't waste too much time on the baby rice/fruit puree stage - I found that DS3 was much keener on solids when I started giving him mashed up "proper food".
As for bedtime with the others I can only sympathise. Mine do have a pretty strict bedtime routine as it is the only way I can cope, and that is with having both of us around to put them to bed most nights.
In case it's any help, here's what we do:
DS1 and DS2 don't have a bath each night, they take it in turns. Whoever's turn it is has their bath at the same time as I bath DS3. I get DS3 out and dry him and dress him while the older one is still in the bath, then DS3 plays on the bathroom floor (or whinges on the bathroom floor) while I get the bigger one out dried and dressed. The two older ones then have supper and watch a video while I breastfeed DS3 and put him down. At 7.15 -7.20 or so I or DH go down and start making "nearly time to go up" noises at the kids, and at 7.30 p.m. sharp the video is switched off and they have to go upstairs no matter how much they whine. Then it's teeth clean and a choice of having bedtime stories OR having a brief play in their bedtime until lights out at 8 p.m. at the latest.
Lastly, please don't be too hard on yourself. You have absolutely climbed mountains since last year. You are doing brilliantly and you are really an inspiration, you know. hang on in there.