Separation anxiety

[Purpleburple123]

My 9 month old boy has suddenly started crying forever when I try to put him down for naps/sleep and he's waking more in the night.

He cries now when I leave the room also.

He's also teething (now has 6 teeth), coming out of a cold and started crawling this week.

I'm so exhausted (he's never been a good sleeper) and hate to hear him crying but unsure if I should stick to my nap structure and let him cry it out so he doesn't learn bad habits. Currently I go in at intervals, pick up, sooth, put down, leave room. That used to work but now I'm doing it for 20+ minutes and he still doesn't settle. I resort to driving him round in the car for naps, otherwise he gets so overtired.

He's on a 3 nap schedule and awake for 2-3 hours at a time with bed at 7.30-8.30. He eats well and breast feeds 4x a day.

Three weeks ago before his cold I was doing sleep training (with support from HV) to wean off breast feeding at night which worked well and he now doesn't feed at night at all. He was sleeping through and waking at 5-6am. Since his cold and teething this all seems to have gone out of the window.

Anyone experience similar at this age. Will this pass soon?

My husband and I have no local support and we are on our knees with sleep deprivation.

Thank you