After reading 
's post wherein he writes a letter to his 20 year old self I thought I would attempt the same thing.
Dear 20 year old me:
Slow down, you think too much.
I get it. I know you think it's important to have a relentless stream of thoughts to guide your daily life, but it's not helping you. In fact, it's probably a large factor in a lot of your stress.
Silence is your friend, not an unwanted experience. Learn to listen to others instead of listening to your doubting thoughts. Again, SLOW DOWN.
Don't worry too much about the opposite sex. Your worry is probably detracting most potential women from ever approaching you or giving you the slightest hesitation.
Being single is great in its own right. Relish the completely open schedule. Embrace the unpredictability of a night out with friends. You have nothing to lose, and everything to gain.
Find some time to develop a sense of your self and your true purpose. You are your own best teacher if you just show up for the class of life as a willing student.
Develop organization for your ideas. And if you have a hard time with that, talk to someone who knows what they're doing. In fact, when it comes to most things, finding a role model or teacher is a good course of action. Learn from those who are doing. Make your flights of fancy and dreams more tangible by meeting people doing that very thing.
Don't view depression as something you must cure yourself of. View it as something to learn from. It is one of the most valuable tools for developing a greater sense of self-awareness and resiliency.
Being happy and up all the time isn't desirable, it actually gets old. People that are happy 100% of the time are likely delusional, crazy, or full of shit. Sadness gives you a measuring stick that, without which, life would be a passing series of average positivity.
Don't ever start smoking cigarettes. I know you intend to quit them by the time you're 30, and I'm happy to inform you that you actually achieved this long-term goal (rationalization), but seriously man, just don't start.
Don't drink so much either. I know, I know, it's a phase that everyone goes through in college, except you can opt out. I'm not saying give up alcohol altogether, just be smart.
LSD can be a perspective-shifting, life-altering, and an incredible tool for transformation. But don't be irreverent about it. It has powerful transformative properties, which can create an imbalance if not used properly.
Set some goals for yourself. You're out of the semi-prison of high school, don't become a prisoner to indifference and inaction. You have achieved a great deal as a writer and editor for your school's newspaper. You enjoy making people laugh and connecting with others. Recognize your strengths, and then harness them with strategies that boost said strengths.
You are a creative individual. But you are also susceptible to impulse and inaction. If you do not use your creative mind, the resulting dormancy will cause your mind to regress.
People generally like you and will confide in you, as they feel your empathetic nature and desire to understand others. It is these qualities that will draw you towards the helping profession, and eventually switching majors from journalism to social work.
While this is a noble and honorably career field, it is one that will not fully take advantage of your creative and connective abilities. You know you don't want to go back for a Master's degree, which is the only real way to advance in the field, so stick with Journalism and keep writing and creating. You can help others with your words and daily actions as much as a social work degree.
Develop a money consciousness. I know, the dollar is the devil, I totally get your rebellious nature. That doesn't mean you need to forsake yourself to a life of poverty in the name of morality. You can be moral and ethical while still earning a vibrant income.
Monetary success can go hand in hand with living out your values. Again, develop goals and a plan to achieve them.
Persist in the face of obstacles. They are learning experiences of the stressful variety, but they are there to teach you.
Buy Bitcoin as soon as you hear about it. Secure it. Hold it. Don't sell it. Your future 3 home-owning self with unlimited travel funds will thank you later.
It's true, your 20's fly by. Make them count, and your 30's will be the best years yet, not something to dread.
Slow down. Breath. You're going to do just fine.