Family member Pet

Our family cat of 18 yes is hanging on to life but we finacially are having trouble to have him laid to rest. With creamation costs we are struggling to put our dear friend out to pasture. We love him and do not want him to Suffer any longer. Rufus is a dear friend and family member. He grew up with all of our kids and breaks our hearts to see him in pain.  Please help if you can.