if you have been in for 3 years you have probably seen the full of it, it is not progressive so doesn't get worse, etc. it is entirely up to you if you can live with a sufferer of aspergers, it depends on if you can accept certain traits. My son is autistic and a sweet lovable person who i think any woman will be lucky to have as a partner
I would strongly suggest you post over on our Aspergers Forum as they understand this condition far more than most of us. I'm sure they have also dealt with people in relationships and some of the issues and problems that arise. I believe they could advise you much better than I could.
As to your question about staying in the relationship, that must be entirely YOUR decision based on the truths and realities of that relationship.
Once you know what those truths and realities are, your options will become clear.
Peace
Greenlydia