Complete happiness is still acheivable even if the circumstances or difficulties in your life seem debilitating. Happiness is a skill that can be learnt.
What is a healthy expectation regarding happiness in our lives? There's nothing wrong with wanting to be happy all the time, but there's nothing wrong with being unhappy either. Sadness, frustration, disappointment, concern, regret and remorse can be helpful energy to move or motivate us to make life better, and give us the energy to reach in that direction. It's when the frequency, intensity and duration (FID) of anger, depression, anxiety, shame and guilt reach dysfunctional levels that problems arise.
But thinking we need to, have to or should be happy all the time, and demanding that of ourselves or life is a set up for ending up unhappy. Demanding anything of ourselves, others and life creates a bigger than helpful or necessary gap between our expectations and reality when things aren't the way we expect or would like. It's like demanding that we or others be and do everything perfectly all the time. We're more likely to find fault in ourselves and others, and get more upset about any fault we find.
We can even end up unhappy about being unhappy the same way people become anxious about becoming anxious. Doing the latter is the recipe for panic disorder ' the former is a recipe for depression.
Ultimately, whether we're happy or unhappy is a product of how we choose to look at things, what meaning we attach to things, what we remember at any given moment, what we imagine will happen in the future, what we focus on, what we compare things to, what we expect of ourselves, others and life in the first place, and how much importance we attach to things.
We make these choices constantly. The ways we do are usually automatic from prior rehearsal. It's why we don't realise we have such choices. One way to increase our chances for happiness is to constantly remind ourselves that we do have such choices, and that certain of the choices will make us feel better, and others worse. With practice, making the choices in better ways can become automatic as well and we can increase the frequency, intensity and duration (FID) of happiness in our lives.