When you stop using it, your skin is no longer accustomed to it. You will need to start all over as a newcomer and go through the "hardening phase" all over again.
Don't ever jump right back in at the full amount (I know, you learned the hard way).
Start over just like you did in the very beginning. Just a pea sized blob once per day for the first week. Same amount but twice daily on week two. Gradually take about 4-5 weeks to work your way back up.