You won't regret it. It is one of the best mangas ever. I am not a yaoi fan but a manga fan and in spite of that Hagio Moto's BL "A Savage God Reigns" ranks number 1 as per to my readings, in matter of fact, it transcends all rankings. Sensei has been able to deliver an in-depth understanding of "systematic abuse" victims and the damage which is done to their brain, heart and soul.
Hagio Moto also provided a comprehensive approach to understanding both the damage of abuse and the constant struggle to provide some form of healing to the victims at the hands of those who care about them (Ian in Jeremy's case).
Of course, there will be several heart-aching episodes but keep reading till the end. It is beautiful and meaningful though there might be some form of ambiguity due to the translator's usage of the word girlfriend in the last chapter. This issue has been tackled earlier by other users and some of them explained the meaning of that word (and of the last chapter in general), so I assure you that there will be bumps along the road but Jeremy found solace at the end (he didn't go back to his old self but he is going to be saved and loved).
It seems that she wanted a new boost, something else than BL so she dropped this one to draw a shoujo which is "Kousoku Angel Engine", but then again it seems that she released a BL sequel for the shoujo back in 2013 which is Kousoku Angel Engine BGH. Both have never been scanlated to my knowledge ... (source: mangaupdates)
It is very unfortunate that she dropped this one. It had a very interesting psychological dystopia theme with main characters having some sort of an oedipal complex and I would have liked to discover this "universe" through Motoni Modoru's eyes. I thought that I was going to find something reminiscent (even if it were a little bit) of Moto Hagio's work (she is a founding figure of both modern shojo and shonen ai) but sadly my anticipation ended with receiving a bucket of cold water on the head!
Have you read "Zankoku Na Kami Ga Shihai Suru" by Hagio Moto? It is a very complicated, realistic, angsty and heart-aching at the same time manga with in-depth understanding of abuse and healing processes.
http://www.mangago.zone/read-manga/zankoku_na_kami_ga_shihai_suru/
There is also "Thomas no Shinzou" by the same author (though the art is very archaic - it goes back to the 70's - and the manga is labeled as shoujo, it is actually one of the early mangas which explored BL themes. Hence "Thomas no Shinzou" should be listed in Shonen ai's pedigree chart, or so to speak).
http://www.mangago.zone/read-manga/heart_of_thomas/
It has also been adapted into a film in 1988 (Summer Vacation 1999) and a stage play.