You first have to decide to move on with your life.
According to the rest of your question it sounds as though this is not something you really want to do.
After 2 years you state you are "lonely and still ache for her everyday...." (This is your choice..)
Every answer you're likely to get is going to advice you to move on with living your life. Most likely your ex has done so.
However if you don't want to move on then you're not likely to appreciate what anyone has to say.
Are you secretly hoping one day she'll come back into your life crying and stating she made a mistake?
Do you believe that with over 6 Billion people on this planet there is (only 1 person) in the world who could make you happy?
Ultimately we all want to be loved, adored, and appreciated for who we are. The right person for you will also know that YOU Are The Right Person For Them. Apparently she was not the right person for you.
It's time you stopped cheating yourself out of a life of love and happiness. There is a woman out there looking for a man just like you and by hanging on to your past you're keeping this woman from entering your life. Right now you're physically available but you have yet to make yourself mentally available.