I'm glad we were helpful to you Tish. Sometimes we just need to stop and get some perspective, hey?
It does sound like he's overtired - the best thing is do whatever works. Walking/slings/feed to sleep, whatever. try to break that cycle.
With
DS I started getting into the habit of walking him mid morning and mid afternoon when he was having 2 sleeps, or going out somewhere at those times, then timing the return for when he was most tired. Sometimes he slept inthe pram or car, but generally he was awake but sleepy so that made it a lot easier to get him to sleep. once we did this for 3-4 days in a row, he got into the habit and it became a new routine. It changes all the time though, and that's one of the challenges i think.
Re bed routine, you could try bringing it forward by 30 mins or so, if you want, just to see if it makes a difference. We eat dinner at 4:30 most days! which is ridiculous, but oh well
Anyway, take care and hope you both get some rest soon.