Poverty sucks, but if you think material wealth is sufficient for or even the key to happiness, then you've already lost the plot.

The key is virtue. Ethics is the science of the good. You cannot be happy as an immoral person. That's where you should look for sources of misery or unhappiness.

(We could also distinguish between happiness and joy, where, according to this distinction, happiness fluctuates because it is dependent on circumstance, while joy is grounded in permanence.)