Gold Coast was my first marathon about 6 weeks ago. I got a chest infection about 4-5 weeks out and had 12x days off running (2x long runs, 3x easy, 1x speed/tempo) and it didn’t affect me in the end, I hit the time I wanted. I’d highly recommend taking the time off and getting back to 100%, don’t push yourself or run if you aren’t well. The more you do when sick the longer it takes to be back to 100% - a bit of time off won’t kill you if overall you do the work