I know exactly how you feel.
It is horrifying how many animals are euthanized in shelters every day.
The way I deal with it is to promote spaying and neutering of pets any chance I get. Also, I vow to only rescue dogs for the rest of my life and never support a "breeder". I also foster when I can. I have adopted 6 dogs myself. I think that's my limit, and it's certainly higher than most people's limits. I sometimes think I could take in a few more but I have to keep in mind that unexpected vet bills could come up. I have two kittens living in my bathroom right now waiting to go to new homes, and I have a colony of feral cats on my porch which I am slowly gaining trust with and I will catch them one by one and have them spayed and neutered.
These issues that you have brought up are exactly what has inspired me to find my life's purpose, which is to help animals in need and bring awareness to people. Keep in mind that there are A LOT of people who are aware, and a lot of people adopting shelter dogs. I have met so many caring people just recently, who are more than willing to talk and share stories of rescuing shelter animals.
It has been a big relief to me to meet so many like-minded folks.
If you are really feeling like you would like to do something to help animals, I'm sure you could think of a way to spread awareness!! Your speech was a great start!! I have a bumper sticker on my car that says "please spay and neuter your pets"... anything is worth it, no matter how small!!! What I do is try to be "pro" spay/neuter instead of "anti" homeless/neglected animals. That way I can focus on the solution and it will help me stay positive. That's one thing I have learned, if you think too much about all the death and ignorance you will sink into sadness. So I just try to keep my spirits up and do what I can to help.