My boss is sabotaging me...

What in the world do I do when my boss is ruining my chances at getting another job? 
I have worked for my current boss for 3 years. I have been an awesome employee and never did anything wrong. My boss and I even became good friends! 
Well due to finances I have to get a better paying job. No harm done, right? 
So I started to apply out. Found a dream job! I got an interview and even a follow up! I thought I had the job in the bag!....until they did a reference check. They called my boss.... I didn't inform her I was looking for a new job. So this caught her off guard. She was PISSED that I was applying out and gave me a bad name. Needless to say I didn't get the job I applied for.
I sat her down and discussed why I was applying out and that it wasn't personal, I just need more money. She was very angry and told me she will start putting ads out for my job and will hire someone ASAP. 
Well today I went in for another interview. It was AMAZING! The lady even emailed me 10min after the interview asking for a follow up. Well after I got home from the interview I got a call from the lady I just interviewed with. She looked up my place of employment and saw my boss's name. She freaked out! She said my boss is manipulative, cuniving, and wicked. She said that she can't hire me because she would lose business if her customers new I worked for this lady. 
What. The. Hell...... 
My boss is ruining my chances of ever getting another job. What the heck do I do now??