Well, I tried to warn you. Selling 1/2 - the safe bet - is one of the most unsatisfying strategies. As you see now, whether it moves up or down, the mind perceives it as a loss, or a loss of gain.
Remember, everyone loses from time to time, it is the LOST OPORTUNITY that can never be erased. Always act with full intent. It is a main topic of disussion in the art of war.
Agree with your advice. The first rule is to not lose money, and to do that you shouldn't regret making money on a sale, even if it goes higher later. One will rarely get out at the top or in at the bottom, so don't sweat leaving some money on the table if you're walking away with a bunch of money.
Don't look back. Take two salt pills and drive-on!
(Oh, and by the way, future prices will fluctuate, and Nokia is a very reasonable long-term hold).