2 1/2 week trip=need help packing light!?

I'm going on a 2 1/2 week trip to France and I need help with packing light! I've always been an over packer and I need ideas since I'm a huge clothes lover! I bought a 33 in suitcase and just found out that my airline won't let me take it! I'm leaving in less than a week and really need help! I was thinking space bags, but my mom said no. If there is anything like that, which would hep with packing light, please tell me. Thank you! Remember I would like to take as many clothes as possible and I need to bring back souvenirs! Thanks.