I've never stopped wishing I fed my girls longer than the few weeks I did, but I try not to let myself feel guilty. When I do I remind myself of the reasons we stopped.
I do admit that a huge reason I'm still BFing DS is to make up for it, but its also for me & DS. I am enjoying it now. I didn't then.
You did amazingly well to get to 6 months
You will feel better soon.