Reflecting bad experience with adviser in graduate school in statement of purpose

I am applying to master program in electrical engineering, but I have some concerns and not sure how to present them in my statement of purpose.

First, my undergrad was in electrical engineering but after moving to US I pursued physics in graduate school. I had bad experience with my adviser. He moved to another university right when I started my research, but since I had a fellowship which came from a school in our university and since he didn't want to pay me, I didn't move with him to the new university. He promised to help me, but didn't do anything after he moved. That being said, since I just started my research and we had a small department in which no one else worked on the same area, I couldn't make progress on my own. But, then I started taking some online courses and became really interested in some new areas and also coauthored a paper in optimization. now I want to apply to electrical engineering for master. I also had to extend my graduate program in physics due to some immigration related stuff, so now my graduate degree took more than five years, while I don't have any result in it. I was wondering how can I represent these stuff in my statement of purpose without hurting my chance of getting admission. I should also mention that I got almost all the PhD courses in physics and have a very good GPA in graduate school.

Thanks for your help!