Seperation anxiety at bedtime pls any advice

[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