Nicotine And Personality Changes

So I've been with my husband 11.5 years (married for 5). He's been a smoker on and off. I've always hated smoking and am allergic. He has "quit" many times... When he quits, and is successfully off, he seems like a genuinely different person - less preoccupied, but most importantly calm, and nicer. Recent past 3 years he had again "quit" and exchanged the nicotine for marijuana. I didn't have a problem with this since I don't see negative changes with marijuana use, if anything he just seems happier on it. Well, in the past few months I noticed a personality shift again - it was like one day he came home and just wasn't the same person. I realized that he's been smoking e-cigs. I can only assume that the nicotine is affecting him again.
Has anyone else noticed significant personality changes on nicotine? What the heck can I do to help this? Apparently this is like a life long addiction. When stress goes up, the nicotine comes back .... :(
Of course, it can changes personality of a man. When ones don't smoke then his/him personality is good but when ones smokes then their personality looks different.
When I quit nicotine I quit other things that I use to enjoy. I think if I had quit smoking when I was young I would have picked a different path in life. I think nicotine changes a person and how they act. I knew someone who got divorced after they quit smoking because he got he couldn't humor his wife as easily. Funny but true. So there's something more to it. :)
Nicotine addiction is sometimes severe too. I know it from the experience of my own family. My grandad couldn't quit as he literally got mad when he wasn't smoking even for two days. I tried to find a solution to this problem, but there was absolutely nothing that could help. Doctor even had to prescribe him antidepressants so he could keep calm and and quit.
Nicotine addiction is terrible. I have written about this and when I did the researcj about nicotine I realised how harmful and terrible it is. I try to help those hwo suffer it and want to quit by emotional support