Saying Goodbye to Donut

It was a snowy winter evening in December of 2010. I had just gotten done at cheerleading practice. I got in the car, to find my mom looking rather depressed and like she had been crying. My nine year old pitbull, Donut, had went to the vet earlier that day because we thought she had some pain in her back. In the previous week, my mom lightly spanked Donut because she had something she wasn't supposed  to have. When my Mom spanked her, she started to yelp and cry. This was not normal considering my mom didn't even spank her very hard.
Anyways, I asked my mom what was wrong. She started crying on the spot, and said that the vet visit was not good. Donut had lymphoma, which is cancer of the blood. I immediatley started crying. My mom then said that she was not sure how long Donut had left. The vet said they could do chemotherapy on her, but you never know how well your dog will react to it. We decided to just put Donut on medication that could keep her alive from a few weeks to a couple months.  I didn't get my hopes up.
When we got home, I just sat on the ground by her and started crying. She got up and started wagging her tail and licked my cheek that was all wet from tears I couldnt imagine losing her.
For the next few days, she was slowing down quite a bit, and I thought the end was coming closer. While I was sleeping, she would come sit next to my bed and cry because she was weak from the cancer and she couldn't jump on my bed and sleep with me.
All of the sudden, she started to do much better, and she was able to jump on my bed again. She seemed perkier, and just happier. But then again, the thought of when to put her to sleep would enter our minds. Should we put her to sleep when she's happy and before she gets extremely weak, or should we just wait?
Finally on February 21, we felt it was time. We put her to sleep that morning, and my mom said it was one of the hardest things she's ever had to do. I still miss her.. so much.                                                

The night before we had to put her down. </3