help, insecurities gallore,

I started dating a guy who is 7 1/2 years younger than me. I'm 33 and he turned 26 shortly after we met. I had no intentions of dating anyone when I met him, but my 12 year old daughter was away for the summer with her dad and my friends kept telling me just to have fun for the summer. Now 5 months later, my daughter is back and we are still seeing each other. He's met my daughter and is over at my house all the time, which I love having him there.

my problem is, I'm now completely hooked on him, and I think my insecurities could ruin what could potentially be a really great long term relationship. I had no problems at first when I went in thinking it was just a fun summer fling but now, I my head isn't screwed on right any more.

I worry about how much older I am, and that he could easily find someone much younger, without kids etc... Why would he want to be with me when he could have the latter. I would like to be able to talk to him about my problem but I'm afraid it could scare him away if he thinks I'm such a week person and full of insecurities, and I'm wondering if I should just walk away now, even though I know it would hurt rather than wait till I know it would hurt even more. As my mother likes to point out, I have a shelf life and I'm not getting any younger and she'd like to see me married off soon.

What should I do?