Have you read How to fail at everything and still win big?
His advice is essentially everyone needs: 1. Good food 2. Exercise 3. Friends 4. Something to look forward to (working towards some goal)
How are you doing in these 4 areas? Tackling the first 3 gives you good energy and general vibe. For #4 there is no end to what can be achieved, so always possible to select a goal. Just need to find something that excites you.