I echo what stonekicker says, once the flat and cats are de fleaed, you need to get some antihistamines into your system, and it will take a few days to build up some resistance.
Zirtek or if you get them from the doctors they come by the name cetirizine, is the only thing that works for me as I am plagued by insect bites in the summer.
When you de flea the cat and the house, dont use the products from the pet shop as they are a waste of money........ get some frontline for the cat, and Acclaim for the carpets direct from the vet or online, (the latter being cheaper).
http://www.vetuk.co.uk/index.php?main_page=ind ex&cPath=3&zenid=d31a3ee88360acbaf17a3c4e72be5 bf1