Hey Susie9, it took me 7 tries over about 3 years to give up smoking and that was pre cancer so don't be hard on yourself. I agree with the others that this isn't the best time to try to give up, but one tip I will give you is that caffeine hits the sensor in the brain that triggers a craving for a smoke. It wasn't until I learnt this and cut down on caffeine that I could finally give up.
Oh, and another tip …. I was still having cravings years after my last smoke.
Be kind to yourself, you have enough on your plate