Do you feel like life is one big cruel joke sometimes?

Yes: Everybody feels this way at some point. It's just part of living life. There are plenty of support mechanisms out there. Seek help if you need it.

Give the joke back: Everybody thinks like this sometimes. Life is unfair. Good decisions (forming relationships with the right people, acquiring skills that are marketable and useful to others, managing time wisely) are likely to result in good outcomes. But best of all, resolve to be kind to others in spite of life's injustices, and without expecting anything in return. "the joke is on you, life!".