Maybe it would help to sort your feelings into a few separate categories. There are
a) legitimate grievances:
As alemci points out, it is extremely annoying to have to listen to complaints from the school because your offspring is not behaving as he should. We've had the laziness too, and I keep assuring the school that we are 100% behind any measures they take to kick ds' backside. Laziness and inattentiveness spoils it for the whole class and you are perfectly entitled to feel angry and embarrassed about that
b) parental dreams:
This is the area where you have to accept that you cannot change other people, you can only change your own reactions to them.
I was surprised to find that ds didn't enjoy reading at all, couldn't care less for the natural world, had no interest in history or art and really didn't see the point in playing an instrument. (I was perhaps less surprised to find he didn't want to join any organised sports either as I hate organised activities myself.) Really, for a long time it seemed as if he wasn't interested in anything.
Lately, partly through my observing him more closely, partly through him getting confident enough to claim his interests as legitimate interests, I have come to realise that he does have interests: they are just things that I have never thought of as interests children should or could have. A bit like my mother never recognised my brother's Beatles obsession as an interest in music; to her, music meant something very different.
c) worries for the future:
This is a tricky one because it does so much seem part of our duties as parents to take thought for the future. But worrying rarely helps things, and quite frequently makes them worse. Worries about a child's social skills or coping abilities can so easily become a self-fulfilling prophecy ("I am hopeless socially, even my own family think so, so there's not point in trying").
Perhaps best to focus away a little bit and remember that "even the very wise cannot see all ends".
On the whole, I think I'd have to say that the things I have worried most about concerning dc haven't happened and some totally unforeseen things have, so the time spent worrying was probably time wasted: I should have spent that building up my own resilience instead.
d) need to compete with other parents
Well, we're only human, it is a natural thing to want.
But I do try, every time I find myself getting caught up in this, to step back a bit and do something that makes me feel good about myself instead. begs the question what I am doing on MN this bright and sunny morning when I should be courting fame and glory by finishing my article