lonniefrances - avoid the anti bark collar and any other aversive techniques. Merlotgran's suggestion is a good one. Google separation anxiety in dogs and you'll find helpful suggestions.
I fostered an 8 month old labrador cross who was being re-homed because of what was described as severe separation anxiety. The dog had been crated, hated it, broken out of 2 crates (astonishing photographic evidence of that)
I went back to basic crate training. Feed the dog in her crate, door always open, everything that happens in the crate is positive, e.g. food, kongs , throw treats in, bits of chicken or hot dog sausage. Encourage the dog to be left alone for very short periods, 2 mins whilst you nip upstairs, close the kitchen door so she can't follow you everywhere. Stair gate at the bottom of the stair or stair gate on the kitchen/utility wherever the dogs crate is.
At night, cover the crate with a heavy dark cover. My foster dog cried fr 25 mins the first night, reducing nightly so that by night 4 she simply went to bed and stayed quite till I came down in the morning. Once that was achieved I began leaving her in the crate during the day. Initially for very brief periods e.g. 5 mins. By the end of a week, she could be left for 2 hours without problem.
Good luck to you - our next door neighbours are very grumpy if any dog makes a noise here, it's nerve wracking isn't it