"It is possible for things to turn out good again isn't it? "
Yes, it is... about 10% of addicts working a strong recovery can remain clean for life. The other 90%, can either go one of two ways, never quit or have periods of soberity.
No reason to make a decision today, watch his behavior, for his words, they mean nothing. Addicts lie and then they lie some more, it is part of the disease.