No and then yes to a marriage proposal

Hi all, i havent done this before but I have searched the internet to try and find someone in the same situation but maybe its not talked about often. In nov my boyfriend of 3 years proposed to me and I said, not no but maybe. I had always wanted to marry him but a few months before we had a rough patch, I have moved to his hometown, and we live close to his mother which sometimes can be a bit hard, as my family and friends live quite far away. To be honest I was rethinking everything when he proposed. it was lovely and he is amazing but in the moment my gut was telling me not to say yes. this was 6 months ago and he now wants an answer...which is completely acceptable as its not fair to go on in limbo. I just feel the moment is gone, plus I have spoken to family and close friends so I feel it will be unnatural and I am just worrying about it in general. I guess I am worrying about everything now, instead of taking a risk. does anyone have advice?