Yes, I was PLAGUED by paranoia at the end of my drinking. It had to do with a combination of withdrawal (which I experienced on a daily basis until I could get home and drink), and the shame from hiding my life from everyone.
One thing about your post--you said you can stop on your own because you've done it before. No doubt. The stopping isn't the biggest challenge with this thing, it's the STAYING stopped. Even when things start looking better in your life. That's exactly when you are most likely to say, "I can deal with it this time, and if things get tough I can always quit again."
Some people never make it back. Are you willing to chance that?
AA isn't the only way for everyone, but it does work for many, many people. If you don't do that, it is still important to do something beyond simply not drinking if you want to stay quit and want to enjoy life sober.