Am I being too sensitive and/or unfair?

I am a very independent person and I’ve been this way all my life. I am nearing retirement. I am in a relationship now for almost a year and my boyfriend wants to get married like yesterday. I have been putting this decision off simply because I don’t even wanna deal with potential backlash for my children since they don’t leave I need to marry again although they do want to be with somebody but perhaps just living with them. I always said that I would marry again after losing my husband nine years ago if I found the right person. The person I am with has many many qualities that I need. But sometimes that he acts in ways that sort of upsets me. It also makes me wonder if he’s the right person despite the way we feel about each other and the qualities that I do see.

Example when we were discussing marriage and he kept on saying to me what is it that you want? Do you want to be alone the rest your life? He further said you know I love you and I would never do anything to hurt you and I certainly would never leave you. He then went on to talk about my late husband and said you know he smoked a good part of his life and he should’ve known that that would eventually kill him. He went on to say my late husbands selfish behavior continuing to smoke and then if he really loved me he would not behave in this way. Obviously, I was very upset because even though I know my late husband should not have smoked for all the years that he did love me and our kids. I also know he did try to take care of himself by quitting cigarettes smoking and only occasionally smoking a pipe. Either way, he certainly didn’t want to leave me and the kids and loved all of us a great deal and once he did get cancer he tried everything in his power to power to to survive. After I told my boyfriend how upsetting this was to be he did apologize several times and said it was really not his place to say that and i explained to him that my husband thought he was take care of himself and try to beat the diagnosis. Is this a really red flag which is something that he could apologize for that I don’t have to worry about? It just seems so self-serving to advance his agenda to for me to say yes to marry him right away and to put my late husband down which is completely insensitive inappropriate in my opinion.

I've been reluctant to agree to marry him but do want to be with him. I can’t say why I’m hesitate. I just am. Maybe I need more time to get to know him or maybe I'm just too scared to fail?