Flea and tick products are often poisonous enough to harm the animals for whom they are intended -- particularly young, old, or immunocompromised animals.  It's a sad truth that the flea/tick remedy/collar companies would rather deal with the very occasional lawsuit (and they are rare) out of court than improve their products.  Maybe things have changed in the last 10 years, but I somehow doubt it.

On the other hand, you cannot just live with the fleas, as they are apt to make you ill, and ticks are dangerous to your animal's health and yours.  In a previous discussion on the forum of this topic, someone suggested diatomaceous earth -- it rips up the fleas' carapaces and they suffocate.  You sprinkle it onto the floors/bedding/etc. and then vacuum it out (I presume you leave it there for a couple hours first).  Borax works the same way, but isn't too great for you.

If you boil down citrus peels to extract a sticky concoction, and apply that to your pet, then rinse, it will get rid of fleas... but your pet will hate it, I'm not 100% it's non-toxic (natural =/= non-toxic) and it's AWFULLY sticky.  I know there are other natural remedies out there but I don't know what they are, and you might want to research their toxicity too.

I'm sorry you're having to deal with this.  But I admire you for investigating before you leap!  Good luck!