I can't seem to get over my ex, it has been 2 1/2 yrs now, he left me for a younger woman, I think of him 24/7.

Join a support group, get some professional counseling. If you continue to do nothing you will be stuck in stage 2 grief for the rest of your life. Not a good idea.

2 1/2 years, get professional help.

If you have to, move out of the house if you are still in the same house, heck move out of the same town if places are that bad to bring back memories.

Start dating, you don't have to have sex or fall in love, but go out to dinner, a show, Get involved in the religion of your choice, do groups, help with some non profit group,