I am an Interior designer who has moved and need advice on how to restart my career, there are complications!?

OK, this is tough. Unfortunately you are stuck with this reference. But you might want to take a different approach as you apply for jobs.

Do you have a portfolio of your work? Get one together and bring it with you as you interview. Are there any clients you have done work for that would be willing to give you a letter of recommendation or a reference?

Do you have a degree in interior design? If so that's a good thing, but you might have to swallow your pride and take a lower level position until you prove yourself.

Be honest when you interview. Work up a statement you can use that explains your previous situation. For example:

I worked at XYZ firm for ten years. While employed there I was in a personal relationship with the owner. Our personal relationship ended on bad terms and if you contact him he will probably give you a poor professional reference.

If you have some clients or other employees willing to go to bat for you then you can continue saying something like:

I do, however, have with me a portfolio of my work and several letters of reference from clients of mine. Here's a list of names and phone numbers of clients willing to speak with you on my behalf to vouch for my professional abilities.

Good luck to you. I hope everything works out.