Afterlife Ideas.
Finding this life worthwhile is a different matter from living with a belief in an afterlife. When religious believers encourage us to put our hope in an happiness in a life after death rather than encouraging us to find it in this one is missing the point.
Everyone has different life experiences and some know hell and some know both. I do experience periods of depression but do have peak experiences too, moments where I feel in touch with the transcendent.
If you get locked in feelings of monotony it is worth considering what you think would make you truly happy. I am not of the belief that happiness is bound to material goals or completely separate from it. Some people have material and social factors to bring pleasure but are still unhappy. Others go through hell by sheer lack, such as the homeless. Even then, a homeless person may experience a greater sense of heaven within than some others although as far as I see it sleeping outside in winter must be horrendous.
I guess the point I am making is that 'heaven' is an inner experience. There is no easy way to get to that. Pleasures and even antidepressants can lessen the experience of suffering but probably the spiritual teachers can lead the way to heaven within.But even this is not simplistic as our own fears and struggles can blind us when reading sacred literature.
Of course there are mind altering drugs, which can bring one to hell or heaven. But this was viewed by Rudolph Otto as profane rather than sacred mysticism.
I am sorry that I am not giving you any easy aid to the problem of monotony. All I can say is that it is possible that we may go through hell before heaven. Or, perhaps you have not been to hell, but whatever heaven is about somehow gaining access to higher states of consciousness pointed to by the mystics and, as their experiences show, this can be in life rather than after death.