So sorry. It is never easy to lose a pet. Eventually the pain starts to fade and it gets easier. Sometimes it is better to just let yourself grieve. Cry it out, make a little memorial spot where you buried them, etc. It may seem silly to some, but we had a really hard time with our shipment of chicks. Only four of 26 made it. The rest were buried under the crepe myrtles in our backyard. To me, it is important to show them respect, even in death. My mom bought me a little solar placard with an angel and flowers that light up at night to mark the spot. When our dog had to be put down, we weren't able to pay for him to be cremated and returned to us. We showed him that respect on his way out, though. My daughter and I gently bathed him, did his nails, and hugged and loved on him until it was time to go.
Making sure that this can't happen again can help your heart find peace, as well. This pet's life won't be in vain if it helps to protect the rest. *hugs*