You have already received some very good advice. It's impossible to help you anymore because there is not enough information here but I strongly suggest that you talk to somebody on a professional basis who can help you sort through this complicated relationship issue.
Have you tried discussing the above with a psychotherapist and/ or psychiatrist?
Do you have any friends and family you can call on at this time? Is destructive the same as abusive? Abusive partners have a tendency to isolate you from your support networks.
There are also other support groups that may be able to offer assistance -woman's refuge, etc. Try looking up your phone book.
As part on my treatment ages ago I was asked to learn dbt skills. They have skills, etc for dealing with different situations. They are just basic life skills.
I'm not sure of a link or web address but they have copies of Marsha Linehan's Skills Training Manual For Treating Borderline Personality Disorder on the net.
If you're in real trouble call the police.
J