Depressed over animal testing?

I recently read an article about animal testing within large corporations and I'm feeling quite bad. The reason I read the thing to begin with was because someone got angry with me fro supporting Proctor and Gamble and their animal testing because I use their product (California Naturals Dog Food). SO, I decided last night that I wouldn't use it anymore and I would refuse to support any company that tests on animals. This was proving difficult in the grocery store (even the all natural store) with the PETA approved list I took with me. Furthermore I have a serious medical condition that I have to medicate even though I hate drugs and have protested the use of with several doctors over the past few years. The fact is there isn't always a natural or holistic remedy for certain diseases. GSK and Lilly are makers of two drugs I take and they are both evil monster corporations. Between P&G, Unilever, Colgate/Palmolive, General Mills and Monsanto it's becoming impossible to purchase safe and healthy foods. P&G gobbles up my dog food company last year. Monsanto buys out Whole Foods this year. Whats next? Can you even flip a light switch without hurting someone or something these days? Am I wasting my time trying to boycott with my wallet when the small companies keep being absorbed by multi-nationals? It seems when we try to use something other than the big companies they simply take away the safer and smarter choices with their almost infinite amount of money. I'd enjoy any positive feedback anybody might have. I feel hopelessly depressed and powerless!