Pain management

A little back story .. when I was in the 8th grade I sprung my lower back as had constant pain for 4 years. During the 4th year after my first injury is when I had my car accident and had a bulge between L3 & L4 and still have had constant back pain for a total of 8 years now . I’m currently 12+2 weeks . I am a daily smoker and have been for 3 years now. I’ve smoked mainly for my pain management and can go about 4 days without it before my body feel like i was hit by a car all over again . My question is am I a bad mom for continuing to smoke( I’ve cut back quiet a bit ) to still manage my pain ? I plan to be cut off by 20 weeks