hi lofty, and welcome to pc. sounds like you're doing a lot of positive things to get on with your life. rather than trying to find a girl to fill the void, i'd try to create a bunch of friends to just hang out with. you've been out of the formal dating scene for a while, so just get comfy with being footloose and fancy free. if you meet someone you enjoy being with go out but keep it light...that way you are giving yourself time to adjust to single life and you won't misrepresent yourself to the girl. working out is great for getting out the kinks in your mind. another good thing you are doing. since you can't work out right now...how bout taking some good brisks walks. you might even meet someone new that way while you feel better in your neck.
if you find yourself getting bogged down with sad thoughts, start singing or do something physical. the mind can't be ruminating if you distract it with something else.(that's why i mentioned singing ).
who knows maybe this time next year you will have lots of new memories to think about!!! bet you that you will. good luck and enjoy your newly found freedom.