Hi
Suggest that you contact Community legal services to see if they can suggest a way forward. http://www.communitylegaladvice.org.uk/
From what I have read freezing orders are looked upon as the 'nuclear option' and can be expensive. I suspect the £15k is just for starters. If this relates to joint business assets, did you take out Business Insurance which included any legal cover. If so, have you looked into whether this would provide any cover.
I don't think you can represent yourself as the process appears to be fairly complex and you could get torn to shreads by your partners legal team. If you do a google search on line, there are various solicitors that specialise in this area.
Huckster