On this one, I believe he is saying that whatever relationship they had has recently changed, and he wants it back to going the old way.
Example: They were just casual lovers and she pressed him for more of a commitment, maybe to move in together or spend more time together... let's get serious now I want you to start thinking about marriage and kids... kind of a move and he went along for a little while and realized that is NOT what he wants and can it go back to the old way that it was??
which would lead us into this line....
He doesn't like how things have progressed and wants out ("off this ride").But now I want off this ride 'cause you're scaring me and I don't like where we're going