You’re sad because you have no purpose, and you probably laze about. If not, you have to become more optimistic which is incredibly hard to do, you have to rewire your brain, you have to realise you CHOOSE your emotions and you allow them, when you realise this and have that power, you have to use it for optimism

So make the most of it, you want to be happier and trust me, we and everyone in this community have your back. Enter open minded, and willing to listen and you'll come out feeling 10x the person you already were. some emotions "just happen" but 9/10 are CHOSEN. My classroom will discuss this. Good Luck