But you are successful. The only way to define success without going Patrick Bateman in the process is by what you've done, not who you are. The fact that you haven't completely abandoned/discredited the identity you held while you made it this far isn't a sign of weakness.
Your success might feel like luck and it probably doesn't feel like you deserve it, not the least of which reasons being that you are a smart dude who is aware of the privileges you've been afforded. Unfortunately, a lot of it IS luck and I certainly don't feel like I've earned my modest success. But to use that as a reason to write off everything you've accomplished through merit is just as silly as thinking you are some kind of living, breathing bootstrap, because I know this might blow your mind, but there are a ton of people born with totally insane privileges you and I could never dream of that still manage to ceaselessly fuck up their own lives and those of everyone around them by virtue of being morons, and the only thing privilege does for them is to keep them alive and out of prison long enough to fuck up again tomorrow.
The hard part is accepting your life has changed because you have changed, and figuring out how to wed the parts of you that haven't changed with this new reality. Granted, most people never achieve that, but if you do, Ghost Carl Jung will enter your dreams and give you a high-five.