This is exactly how i feel right now. I am, by unfortunate circumstances, the only designer in one of the offices of an enterprise company being ran by dev-minded people. I know my weaknesses and strengths, but I need a design-influenced team and company for me to better than what I'm outputting right now.

If I were to look for a job now with a portfolio of the products I've worked on at the company over the last year, it would definitely be an uphill battle.

You're not the only one. I wouldn't categorize my current place of employment as "enterprise", but it sucks not being able to design to your full potential. It's an agency, so you can't give the client the best you can do unless they're willing & able to pay for that (and many aren't).

I'd recommend doing as many side projects as you can. I know it can be hard to find the time (I have a one year old son so I'm familiar with the struggle) but if you can put something together over a few nights/weekends, and really design the hell out of it, it'll make stomaching your day-job constraints much easier. Just remember the Sex and Cash theory: http://gapingvoid.com/?s=sex+and+cash+theory What you do at work is strictly to pay the bills. If you happen to enjoy it sometimes, great; but remember that what really matters is what happens outside of that.

Another example: I used to flip burgers, but I enjoy cooking at home. I wasn't ashamed of the nasty food I pumped out of that fast-food kitchen, because I knew it wasn't a representation of my cooking abilities, it was just what I did to pay the bills. Apply the same thinking to your situation.

Is Facebook today that unlike those enterprise companies? How much freedom do designers have to experiment?

Finding developers wasting away in cube farms is quite a similar experience--there are a lot of strong hires out there that have simply been underemployed.