Start with coffee. Coffee gives you a good kick, the way you need right now: a little adrenaline and dopamine. And, of course, you're addicted, so coffee always makes you feel better anyway.
Don't spend too much time on the internet. The internet is a big black whole of information, a place of creativity and genius, and sometimes a big sucking void of loneliness. Nothing you find there will make you happy.
Build a city out of the coins on you've found on your floor, write letters, draw a picture of your heart, even if it's bruised. Stack the furniture: bookcases on top of desks, end tables teetering at the top. Then rearrange it, something completely new. Put your desk in the kitchen and your bed in the dining room. Clean up your mess, sweep the floor, wash the dishes.
Make dinner. An omelette maybe, with vegetables from the stand down the street, and the heavy cast iron skillet from the thrift store. It's delicious, because you made it.
Read or watch a movie, don't watch much television. Good books are whole things, works of art. So are lots of movies. Television always leaves you hanging. Characters that seem like friends for a moment, and then leave you unsatisfied, like your empty apartment after a party, where all the guests hardly knew who you were.
Don't spend too much time alone, though. Spend time with all those people who love you. You can't be whole without your heart, so when that occasional heartbreak comes along you have to hold on to whatever it is that you love and that loves you back. Maybe the future is nothing like you hoped it might be, maybe you completely misunderstood yourself, maybe you said things you shouldn't have, maybe you can't get a handle on it all. Forget it. Go out. Get real drunk. Fall in love again and again and again.