Macky's mom that's how I was with my Lucy. Though she had a drug resistant infection (UTI) that eventually spread despite our best efforts. I was in your position a little over two years ago, and I laid on the floor with her in the vets office as she took her last breath. In that moment there was no place else I would have been. There for Lucy. You did the right thing for Macky no mater how hard. I won't say it's been easy, but it's become easier for me to remember the good times, rather than the last few months / weeks / end. I keep her picture with me at all times.
Take the time you need. If taking sometime off work will help do it. If taking a short relaxing trip will help do it. If anyone doesn't understand don't make it your problem. We all grieve a little differently, but remember to grieve the way you grieve and don't worry about the rest right now. Take care we are here for you.
Lucy's dog Daddy forever.
It is better to have loved your fur baby, and lost him or her to the rainbow bridge than to have never loved at all, for we will meet again.