Some of the works you listed are feelings that perhaps you can change if you think about them differently. He probably doesn't think of himself as a disappointment and may not really be able to stop being irritating or frustrating so can you try to re-frame your feelings in a different way? I know this isn't easy - I'm trying to it with my feelings about my 4yo!
That is a very good point. I think part of my disappointment is in myself for not loving him the same way I have his whole life...does it mean I am a bad mom or not loving? I know I am irritable in general sometimes these days, too, but it seems like we sometimes can't be around each other for five minutes before I am annoyed at something he does or says. His dad and I are divorced, and I get very bugged about mannerisms he has that are his dad's. OF COURSE I KNOW (please nobody tell me how awful I am) that this is not his fault or anything, but it's also not my fault that it trips my wire. The best I can do is just pay attention to how I am feeling and why and try to kind of self-talk myself out of the irritation.
Another factor that makes parenting him very hard is that I was molested by a teenage boy for years. Yes, I have had tons of therapy and realize there are transference issues...but those "ick" feelings that I sometimes have about teenaged males hop over to my son...and, again, the best I can do is pay attention to where my feelings are coming from.