Condoms are a little restricting to sensations, see the second half of this post. When I first started having sex, it was months before I actually ejaculated while inside my gf - for some reason I just couldn't. I wouldn't worry about it, it could be a comfort issue, just got to get comfy with your surroudings. Don't worry, nothing is wrong with you, you are not abnormal.
As for condoms, checkout some thinner condoms geared twoards pleasure. I suggest trying a variety of them and then finding the one that fits you best and that you like the most. You probably have little variety at the local drug store and theyre probably sold in big packs as well. Check out this site:
http://store.condomsdelivered.com. They allow you to order single condoms from their selection of 100s of condoms. Also if you order 10 bucks or more worth shipping is free. (No I am not affiliated, just a happy customer).
I also suggest trying fitted condoms sold at condomainia.com, They are custom fit to your penis at a decent price, They made a big diffrence in bed with me they fit perfect, better sensation, and not annoying to wear.