I would suggest you begin by crate training Dutch now and beginning to alone train him also. It's really good that you can be home with him during the training process because that's important, so you have until December to sort this.
Here are some links - firstly I would suggest you don't leave Dutch alone for longer than the amount you have "trained up to" if at all possible, because you don't want him to "practise" being distressed when you leave - the more a dog behaves in a certain way, the more he will behave that way in future. So take him with you if possible or get a neighbour or friend to stay with him.
To begin with, you'll need to follow the crate training link to get him used to a crate (which will help save your back door).
Then you'll need to follow the Separation Anxiety link - ignore the drug treatment suggestions - if you follow the behavioural suggestions it should be enough.
http://www.ddfl.org/behavior/crate-train.pdfhttp://www.clickersolutions.com/articles/2002/sa.htm