Yes, I would attribute my decrease in sex drive to nandrolone. Prior to my use of it, my sex drive was very noticeably higher. Also, coupled with this is noticeably weaker erections.
I've never needed to control estrogen much. I can think of a handful of times in the past 12 years since using exogenous hormones that I've taken arimadex to alleviate a slight increase in nipple size due to a sudden large increase of testosterone usage: say from 500 to 750 mg. Or to be extra "peeled" when dancing on stage (I used to be a male dancer).
It's also worth noting that I do have slight gynecomastia from puberty. I remember being a kid and having severely sensitive nipples. My mom would put band aids on my nipples so I could wear a shirt to school. It is still there and comes and goes a little depending on diet and ambient temperature. But it is not a severe case.
Earlier bloodwork did reveal higher than reference range values of estrogen but nothing really to be very concerned about.