Updating SF86 before any interviews have occured

I have an interim secret clearance that I’ve only had for about 3 weeks now. I have not been interviewed about it yet nor have any of my listed contacts, to the best of my knowledge. When filling out the SF86 I got some bad advice and omitted all my past drug use. This consisted of marijuana use 3 moths prior to my SF86, along with MDMA, LSD, Shrooms, and cocaine usage 2 years prior (only used a few times). I have an SF86C to update my address, should I also list my past drug use and hope the mea cupla works out? I dont want to lose my interim clearance but I also want to be able to get a TS in the future. Am i screwed?

at this point you either keep your mouth shut and stop using. Or tell the truth and lose all your chances of being cleared ever.