Smoking

I'm 14 weeks pregnant & was quitting smoking. Told my doc at the 8 week visit I was down to 3 a day which was true. Then the father walked out on me at 10 weeks over something very petty. I'm 37 years old & this is my second child. I know I need to quit & I know it's completely selfish but I can't. Since he left all I do is try to keep myself from crying at work (I'm a teacher), cry in the car, cry at home. Cigarettes really help to calm my anxiety & stress. Any tips? Please don't bash I've been through enough. Thanks