how to prevent?

lately i have been playing more tournements online than before. but i seem to always get into the same problems, one way or the other.
if i play tright aggressive and build up my stack patiently i normally make a call later, after which i ask myself why the h... did i call that, even though there were enough out, but didnt hit it. so i know discipline is needed and all, i just break soetimes.
the other thing i am facing is not building fast enough, so the blinds eat me, and then when they are like 100/200 i sometimes go allin hoping and thinking " geez, gotta get this one "

i know this may sound stupid probably to most of yall, but i would really like to avoid this stuff and improve so any advice would be much appriciated.