Don't be afraid to commit - do it early and build a life with someone, if that's what you want. The grass isn't always greener elsewhere.
Live for today, save for tomorrow - invest in your 401k, and get an income/rental property. If you like it, get another. You won't regret it when you retire at 50 while your friends are working another 15 years.
Spend time with the people you love. They won't always be within arms reach.
And last, don't stay in a toxic, broken relationship, whether with a girlfriend, wife, friend, whatever. Cut your losses and don't look back. It won't get better - don't spend years "working on it". It ends up te same, the only difference is you're older than you would have been.
Oh, and PLAY PINBALL!