It won't be burglary because there's no intent to steal, the property inside being yours or reasonably believed by you to be yours. Indeed you have an action in the tort of conversion if he is retaining your property in this manner and stopping you from getting it, but this is more theoretical than realistic.The court route is the best when a wife has left in this manner.
There is perhaps another route, which I have witnessed happening. A friend left her partner, They were not married. He was being obstructive and didn't want her in his,solely-owned, house, even to collect her own property. The police had a family liaison officer, or some such title. She arranged with the partner to be visited by police officers and my friend. My friend did not go in, but relayed instructions to the officers as to what to fetch and where it was and they brought it out to our cars. Subject to the amount and extent of the removal, I expect,this process would be applied in other cases.