Problem looking in his eyes.

So . I've been with my fiancé for over a year and a half.-and well. I still can't look into his eyes while talking or anything ....I can look in anyone else's eyes just not his....I know it's an insecurity thing but...idk... If you guys have and advice or help please let me know if love to hear it. I have tried working on it and he wants me to look at him but I just can't and it's the same for sex. I can't look at him or I don't like having sex where the room is lit up it either has to be dark or if it's lit up we can only do missionary be because I don't want him looking at my back or anything like that it just makes me insecure ....help?