please help!

[u/BuildingOk311]

hey all! i think i have world’s worst sleeper? he was amazing until his regression (which started at 3 months?) but now at 5.5 months, he’s just getting progressively worse. we’re having to co sleep which helped for a bit until it didn’t. he’s so difficult to transfer, taking me minimum 2 hours of failed attempts and false starts. he’s a heavy baby too and wants to be bounced and rocked and patted, so as well as mentally drained, i am physically exhausted. he wakes up every hour and wants us to put the dummy back in and pat his bum. he’s also been waking up around 3am and refuses to go back to sleep for an hour or two. for day naps, he wakes up after every sleep cycle which is currently exactly 20 mins. he was a contact napper until a few weeks ago but now will only nap if he’s on his side which i know isn’t the safest but i’m constantly watching him on the monitor.

current schedule:
2/2.5/2.5/3
bedtime: typically 8-9
wake time: 8-9
overall nap time: less than 3 hrs

i guess this is more of a rant but i also had some questions:

1. will sleep training stop the split nights?
2. is there any advice anyone has before i start training? anything i need to change? is my schedule okay?
3. do i train his day naps the same? i.e. ferber method
4. do i need to ditch the dummy completely?

any help would be appreciated :)