Pls help with any seperation anxiety tips!

[BettyBoo246]

My ds is 7 months old and for the last 2-3 weeks he has been suffering terribly with seperation anxiety day and night! I can just about cope in the day but putting him down at night is becoming such a nightmare :(
As soon as I start walking to his room the tantrum starts, he will scream and scream and then some. I've tried leaving him to cry it out, doesn't work, gradually leaving the room doesn't work!
Please if anyone has any advice I would be grateful

Mine didn't like going to bed at this age, but it was because he wasn't quite tired enough - what is his napping routine like? Could he have outgrown a late afternoon nap? That was the issue for my DS. Too young for tantrums at that age I think.

Well he is still tired 2 hours after waking up at the minute, he'll wake around 7am then 1st nap about 10am till 11.30, then 2nd nap is 1.30 till 2.30 and then he will need another one at 4.30, I try to wake him at 5 to 5.15 on this nap but he doesn't like it and likes to go till 5.30pm then bed at 7.30pm
I have wandered if this 4.30 nap is doing more harm then good but he does get even worse if put to bed when overtired

His routine sounds fine, it's so tricky at this age! Have you tried just sitting in the room till he drops off? I used to pat DS's back till crying stopped, then sat in a chair in the room shh shhing till he dropped off. Took ages the first few times, but got better within a few days. It's like the wussy version of CC :)