I know it is very hard to "trust" him again, but you've got to step back and allow him to grieve the loss of this woman. It is more difficult for him to mourn the loss when they are working in the same place.
Both of you have shared some personal feelings w/each other. Now, you will need to step back and do not bring up the ow again. You are allowing her to have entirely too much power over your situation. Put thoughts of her in a box and stomp on it.
Reconciling after an affair is difficult for all concerned, but most importantly trust has to be earned and your h will need to earn your trust once again and he will learn this as time goes by.
Try to enjoy your time at the cottage...leave the situation at home and just enjoy your time w/your h.
Hang in there.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.