Hi Fidget and welcome!
Yup, cigarettes, can be a nasty little addiction. Though I was able to quit drinking I still smoke, and am working towards giving them up to, but it's a highly addictive little stick isn't it. It sounds like your allowing that to be the reason your using other substances, so what to do? Well I'd like to suggest you visit our NA and Substance abuse forums allon with Nicotine forum.
You will see the horrors addictions caused us here. You will see the difficulty we endure in quitting and getting clean and sober, but the good news is it's never to late to quit, seek out help, and take back control, before it get's out of control. So Stick around, have a read through the various forums, and make a firm decision about what you need to do, and know there is plenty of help in doing it.