Ok, I don't want to scare you away. Getting past 90 days on your own is pretty bad -ass. You're probably thinking you may not need to go to extreme measures like getting involved with a bunch of strangers on the internet and holding yourself accountable. All the more power to you if you can keep it up without an extra kick in the ass. I know I hated the idea...at first, but I was eventually humbled by my addiction.
If you don't want to join up with a group, that's cool. You don't have to make up any stories for not doing so. Just know that if your addiction throws a sucker punch, there will be people willing to bend over backwards to help you stay quit. But you have to be willing. You aren't there yet.