Separation...need advice

I told my husband he had to move out for a little while last night. I’m still in shock that this is even where we are at right now. We have a 2 1/2 year old and a 4 week old and I felt like I was drowning before this. I do not have any family nearby I can count on so I literally have no help. My husband and I have major trust issues due to the fact that he has lied to me for years. The major reason he lies is to cover that he is smoking. My mother died from lung cancer in 2012 when I was 24 years old and my husband and I quit together vowing we’d never leave our kids in the position that I was in dealing with such emotional heartbreak. I thought we really had both quit until I got pregnant with our daughter and I started smelling smoke on his clothes and mouthwash on his breath to cover the smell. I brought it up to him several times and he denied it so I let it go, I guess not really wanting to confront that he was smoking or was lying to me again.

Fast forward to my daughter’s first Christmas and after a beautiful morning my husband goes to the garage to throw the trash out and there I actually catch him in the act smoking. I was stunned, hurt, furious. He lied, made excuses that he just borrowed one from his father and that he’s never done this before. But of course in the garage I find packs of cigarettes, gum, etc. I forgave him yet again.

The next year I miscarried and after finally getting pregnant again I saw the signs smoking. In this time gap he had continued to smoke then lie then get caught and then I would forgive him. I love him and our family and was just hopeful he would change. This time when I caught him, I begged him to tell me the truth and we would work on it together but he continued to lie and tell me I was paranoid. He even swore on his unborn child’s life, our rainbow baby, that he wasn’t smoking. I caught him 3 days later.

Now, it is our son’s first Halloween, another holiday memory and experience ruined by this. I caught him last night again, this time he hid them in the ceiling of our basement after made me feel crazy for 2 hours saying he couldn’t live in a marriage where everything he did was questioned and that I should begin trusting him again. Wow. I’m just heartbroken and don’t know how he could do this to me, after 2 kids and seeing me utterly exhausted these past few months. I don’t want to be with a person like this. I feel cheated by him on what this has done to our marriage and don’t know where to go. I don’t want to break up our family but I don’t want to live constantly questioning what he is doing and if he’s lying. Smoking is a deal breaker for me because of losing my mom, so it’s not something I can get past. We’ve tried therapy before. What would you do?