What Are The Ill Effects Of Drug Abuse?

My husband is an er physician. 20 years ago he had a serious drug abuse problem that he hid from me. His drug of choice was fentanyl. He was taking used syringes out of sharps containers and shooting up. He over dosed on Sufenta. He mistaken it for fentanyl. He was sent to Talbot in Atlanta for 6 months. After treatment he did his 90 meetings in 90 days. Nothing since. In April 2010 I discovered he was watching pornography in the middle of the night as I slept. I was completely shocked because this went completely against HIS values/morals. I had never viewed pornography myself. He admitted that this had been going on for approx. 5 yrs behind my back in the middle of the night. He found a marriage counselor for us to see. My husband said that he turned to pornography because he and I were not intimate enough. Since marriage counseling he has wanted sex from me on a nightly bases. It became very mechanical and the expression on his face looked like extreme high. He even wanted sex when his father suffered his first stroke. I though for sure he wouldn't want sex that night! In Aug 2013 I discovered he was engaged in an extramarital affair with a nurse at the hospital where he works. Much more I could say but that's the basics. We are divorcing. I believe he is a sex addict. My question is, if he has unresolved issues which lead to his drug abuse years ago, could his addiction have crossed over to sex addiction? I here he looks absolutely terrible...skinny, gaunt, gross, pale and acting paranoid.