mintymintymid...you are so young and this diagnosis seems a bit much in my mind (not to say it is not so). My specialist says that adenomyosis is generally found in women who have already had children and usually they are older. Now I'm not saying he knows it all... I guess, if I were you, I would go get a second opinion from a 'specialist' in the field of reproduction.
I know that I was diagnosed (90% certainty) in August 2006. My fiance and I had practiced safe sex until December 2008, as we just weren't ready for another child (my girls' are not his). In the past I could just
look at a penis and get pregnant! Now...here we are six months later and we are still unable to get pregnant
If you get a second opinion and the doctor tells you the same thing, I would have a sit down with your guy and tell him how it is...either get going on it or risk the chance of it never happening (unless you want to go the IVF route).
Hope this helps. Message me anytime if you have questions. Sometime information from people who are going through what you are is the best way to deal and heal! Take care.