im going to say, walt was doing just fine til skylar walked into his life. his life has been a downward spiral from that point on. when he was with getchen and gray matter it seemed like the world was walt's oyster. the blank pages between that point and why he tossed away a billion dollar business to play a pussywhipped high school teacher with a mentally deficient son still needs to be filled in.
my theory, walt got a boner watching the crossword puzzle waitress(skylar) ,which pissed off gretchen and she cheated on him with his partner and that caused the bad blood, then oops! crossword waitress is now pregnant so he had to do the right thing and marry her and settle down. he quickly sold his business to pay for the new start on life. buying some baby furniture along the way. sure nobody made walt put his penis in the waitress, still she was the cause of all his problems. make no mistake, skylar is a bitch, she has no friends, the only person she talks to is her sister, who she is a bitch to as well