Just to be clear, it's a matter of not having the time to go out and socialize? If it's the case you have work, I recommend finding a local spot amenable to working at (e.g. coffee shop, bar, library, etc) and becoming a regular. Go almost every day for a few weeks, and get to know the people who work there. Aside from the perks you'll get as being a regular, it's also give you a nice dose of friendly non-work-related social interaction.
Turning towards creative endeavors as you've mentioned is also a great distraction, though doesn't solve the issue as well.
Last, even though you're busy, if there's any way you can do it - try to set aside one night a week to devote to hanging out with your friends. Doesn't have to be an all-night bender, either, and no shame in turning in early to work.