Feeling very defeated and ashame

I’m 33 weeks pregnant and before I got pregnant was I was heavy smoker , smoking half a pack of cig everyday , every since I found out I was pregnant I’ve tried to slow down , only smoking half a cig and throwing away the rest . Now it’s getting to the point where I can barley breath through out the day , I wake up choking on my own salvia cramps every time I smoke one (small cramps ) . Why is it so hard to stop after ever cig I tell myself no more I’m hurting my baby I need to stop , I love him so much already but I just can’t seem to put the cig down . Especially that every one around me smokes heavily and I’m constantly around cig smoke . Is there any tips somebody can give me ? I wanna stop for the 6 weeks I have left . I feel so disgusted with myself . I’m ashamed being out in public I literally hide when I’m craving a cig I don’t want any one seeing me . My doctors says atleast I don’t smoke a whole pack and a half a day . I drink plenty of water and eat the way I’m suppose to hardly no snacks . It’s just the fucking cigarettes I WANNA STOP SOOOOOO BAD , is there a petition to get the store to stop selling cigarettes!!! Jesus’s ! Somebody help my poor baby is probably suffering. I pray for a healthy pregnancy and great delivery. Smoked my last cig 45 mins ago . Challenging myself to not touch another one ! I got this