You can definitely find more happiness, more satisfaction if you do this practice. I I am a living proof of that, but things will still come to you that are unsatisfactory. Dukkha will still exist, even for the Buddha, Dukkha still existed. The Buddha had Dukkha in his body. In the scriptures, I believe there are three occasions were the Buddha says to one of the other monks, "Sariputta, you teach tonight, my back aches, I am going to go lie down". So even the Buddha had physical pain, we are never going to be rid of physical pain until the body is dead.
He also had Dukkha in the sense that some people tried to kill him, others abused him, these were unsatisfying moments in his life, where he was being attacked and blamed, etc. So you're still going to have these things, even if you are fully enlightened. But a fully enlightened person doesn't suffer from them, and this is what we want to do in our lives. Whether we become enlightened or not, when the Dukkha comes, we want to change our reaction, so we don't suffer from it.
You also have to do the Unpleasant Physical Sensation techniques if you want to lessen physical pain coming to you, which in turn may bring you mental pain.
So Dukkha will still come, but your reaction to it is going to hopefully get better and better so that you don't suffer the extra Dukkha in your reaction.