A few things...
I've been dealing with sciatica for a few years off and on as a result of a sports injury that I tried to fix myself but likely prolonged because of my approach and because of bad habits.
Basically your core muscles are weak or compromised or simply aren't being activated properly. Don't fret just yet because 90% of sciatica issues come from the fact that most of us spend too much time sitting AND in improper ways. I have a desk job so of course that doesn't help, but the initial sciatic flare ups could have been fixed, had I addressed them early on but alas, hindsight is 20/20.
First things first....DO NOT LET ANY DOCTORS GO IN THERE. Steve Kerr (coach of the GSW) has echoed the same sentiments.
Go see a Chiropractor first and foremost. The hardest job will be finding a GOOD one. Try to find one that has a history of dealing with clients that need SPORTS PHYSICAL THERAPY, otherwise you will tend to run into a lot of quacks and those are the ones that give the field a bad name.
You need to get X-Rays to see if there are any issues with the spine itself. Might be a herniated disc OR it could just be an issue where one of the discs are being pressed on and so you'll need some adjustments so that your back will...for lack of better phrase...remember the way it's supposed to be, as opposed to whatever state its in. You're a young dude so there's likely not that much long term harm if any so don't panic.
Next? Heat....when you get home, get yourself a hot water bottle
or those electric heating pads pads and put that on the area where there's pain. That will alleviate the tightness that is no doubt causing a great deal of the pain in the lower back, because it could be the muscles pinching on the nerve. It's even better if you can put it between yourself and your chair at work.
And speaking of your chair at work....GET YOURSELF A WEDGE. Some places call them a sacral wedge as well. It looks like this....
This will allow your sacrum (basically your tailbone) to DROP and thus allieviate tension on your discs, while also, forcing you to maintain proper posture while sitting, thus activating your core muscles (abs and obliques)
Once you're sure there are no serious spinal issues and that sacral wedge starts doing its thing, I guarantee your sciatica will start to fade.
Also, start eating anti-inflammatory foods as much as possible...TURMERIC my friend, and make sure whatever you it with has black pepper in it so that it can activate the turmeric's anti-inflammatory properties.
Also...go get a massage. Find somewhere that specifically specializes in myofascial release and muscle activation, so that you can loosen those core muscles (which support your overall posture!) and get them to start firing on all cylinders again.
One final thing...if you have been squatting at all in the gym? STOP. NOW. ESPECIALLY IF YOU'VE BEEN DOING REAR SQUATS WITH HEAVY WEIGHT. I'm not saying you're going to have to stop squatting forever but if this applies to you, you're essentially pulling the rope at both ends.
If you live in the NYC area I can recommend a few places to go for treatment...good luck
