4 month sleep regression

[rosey82]

I'm really struggling at the moment with DS sleeping. According to wonder weeks we've got 9 days to go of the clusterf$&k that is leap 4.
He started having at least 1 decent nap a day (1.5hrs) and was doing a 6 hour stretch at night. He did that for about a week, then had a massive growth spurt so was feeding a heap, but since then he will not nap for more than 40 min in the day and goes to sleep fine, but needs to be resettled sometimes hourly overnight. 3 hours is the max I've got overnight in the last week. Every sleep at home he is put down the same: lights off, swaddle, music, cuddle, off to sleep just fine, sometimes I have to go back a couple times to pat him, but he just can't seem to sleep longer chunks! It's doing my head in!
Im a grumpy cow right now, I'm not dealing well with DD (2.5), DH is working crazy hours so not much help. Even when DH takes him so I can have a break on weekends I just stress about what have I done wrong that this child won't sleep?
Unfortunately because I have to be out with DD, DS has to have at least 1 nap on the go so staying home all day to work on naps is just not an option.
I've even considered trying him on a bottle of formula at bedtime to see if it works, although I know it probably won't help with sleep.
Plus the fact that his naps are so short he ends up awake during DDs nap time so I don't end up with any time to myself all day - I need alone time or I turn into a crazy lady.
I don't know what I'm writing this for, maybe just a vent, reassurance it will get better?
Sorry for the ramble.

[binnielici]

Hugs. Not much advice. DS3 (6 months) on my chest in a wrap right now. His first nap of the day - yup been up since 5.30am.

Just a whole lot of sympathy xx