You diagnosed the problem very precisely..... you take forever to move even when the moves are obvious. Not every position justifies using a lot of time. Some positions do. One of the problems with doing tactical problems is that when you are playing a game you are inclined to think every position is like some "White to win" tactics problem.
Study tactics differently for a while. Look at simple problems and when you look at more complicated problems don't try to solve them, but instead just try to identifiy the elements -- over worked piece, back-rank weakness, unprotected pieces, etc. That way, you train yourself to look at a position in a glance, and determine whether or there may be a tactical solution OR if a the position just requires a developing or repositiong move or make luft, etc.
Also, avoid openings that have a fluid pawn structure, since strategic plans might have to be re-examined after a change in the pawn structure. Any opening with a pawn chain (advance french, caro-kann, etc) will generally narrow the number of variations to be considered.
I'm a slow chess player. I take forever to make my moves...even obvious ones. I have been playing 30 minute games here on chess.com and I feel bad that I use almost all my time. If I'm lucky, my extra thinking has put me in a won position that I have to try to win quickly. Other times, I lose, and I notice that my opponent has used much less time than I have.
I haven't played in rated USCF tournaments in years, but I would always get into time pressure. I want to figure out how to force myself to think more quickly, manage my time time better, and know when a position requires me to utilize those precious extra seconds or minutes on the clock.
Any ideas?