Voting Mistake, Stupidity?

I do not consider myself a stupid person, but i made a very bad mistake. I have always been a regestered republican, i am 52, when George W. Bush authorized the attack on Iraq, i was angry. We were already at war with Afganistan, Iraq was all bottled up with nowhere to go. I changed over to independent. I did not know untill i went to vote today i was NOT allowed to choose the person whom i wanted for state Govanor, or Senator. I was only allowed to choose ONE Judge. Needless to say, i was mad, at myself. I did not do my home work, i did not reserch the rules. I was mad at the system, am i not an American? Why do i have to be in a party? I want to vote for whom i like as an indavidual, not as a group. Does anyone else see something very wrong with this system? Are American's rugged indaviduals, or a meek collective? Ok enough ranting, i just hope this helps others from making the same stupid mistake i did. God Bless America.