I second most of the advice presented here. Most great DMs start off as poor or mediocre DMs and work their way up. Over the years I've probably made every DM mistake possible. Nowadays, not so much. If you try to get better, you'll get better. If everyone is having fun, or at least engaged...
I had a 3E DM that created a campaign where equipment scarcity and attrition was to be a core theme.
He was quickly flustered by the caster and monk-centric party he ended up with.
I don't think weapon breakage adds anything to the game. If you want to 'force' the GWM fighter to use a...