Help finding a manga/mangwa!!!

Hi! I remember it had to deal with a serpent god/spirit of some sort. The Mc has white hair, he is in college and has a snake tattooed around his body. After meeting the spirit in “human” form he starts having really weird dreams of the snake basically assaulting him and start getting really tired. He tells a friend and he ends up going to a far away town to look for a shaman to make that go away. He ends up at the spirits house whom he had met before and he tells him that the snake, it is really attached to him and that he is going to have to “purify” him through sex lol. As time passes the Mc becomes more comfortable and slowly starts forgetting that he was only supposed to be there for only a while. They end up together and the spirit confesses that he couldn’t save Mc from a tragedy in a past life and that that was why he was helping him now. It then cuts to their previous live, where the spirit was a lower god and could shift from snake to human and that it how they met. The Mc was from a really poor family and was indebted to everyone. As such, they wanted to give him as an offering, they ended up raping and killing the Mc before he could back to the spirit and as such the village was condemned to many years of suffering and death.

I’d really appreciate it if someone remembered this one please