Life is what we think it is: it’s the sensory input and then however we interpret that.
Much of our suffering is caused by ourselves, because if we would have thinking skills we would focus to what is best at each present moment, instead of thinking too much of the past or worrying about the future.
Our life is a construct of our thoughts and these feelings that follow. And yes through conscious thought intervention (called stopping and thinking) we can actually affect how we feel in the long term. Actions lead to results, which come back to us as feedback which causes feelings.
What is in our control is our attitude towards life.
If we think like is cool, then it is cool. What we focus on grows stronger and we will find the strength to live.
If on the other hand we do not see life as an opportunity, then we the negative begins to strengthen and grow, which then in turn causes more negative intended and unintended consequences.
What we focus on, grows and determines how our life is. We have the choice.