Every person living in the Divine Will should set a goal of being the best sufferer. If you have a suffering that is particularly burdensome, making it difficult for you to smile, take the time to imagine the good coming from the offering of that suffering joined with the Cross. Imagine souls saved, natural disasters diverted, great conversions taking place in the government, mercy and graces poured out on sinners, souls snatched from hell…
See the Father looking down on your country and the whole world and not sending a much deserved chastisement, thousands of Jews having visions of Jesus and accepting Him as their Messiah, the Blessed Mother appearing in more places…
You can go on as long as necessary. Now look back at your bothersome suffering and weigh it against all the good you have imagined. This will make it easier to carry on with a difficult suffering. Jesus looked at His cross and measured the length and width of it to make sure it could contain all souls. He saw billions of souls in heaven with Him weighed against 3 hours of suffering on the Cross. It was an easy decision for Him.
Take a closer look at the good you are doing with your suffering and this will make it easier to smile.