Liz, first, I just wrote you a very long response, and accidently deleated it. So, here goes again. Talk about sitting too long!!
I have had 3 discectomies already. The first was thoracic (behind my bra strap). I was told absolutely nothing for 4 weeks afterwards. I did OK. The 2nd. was at L4-5 level. I was told 2 weeks to not do anything, and then slowly return to normal. After several months, I developed scar tissue. I had sciatica on the same side as the surgery. I went for nerve block steriod injections, and they really worked. Then, I herniated the L5 S1 disc so bad, that it required surgery rather quickly. After that surgery, I was told absolutely no lifting, bending, twisting or driving for 6 weeks. This new surgeon told me that that is how long it takes for the part of the disc that is still remaining to heal properly. He also told me that once someone has a discectomy, you have a high chance of reherniating the remainder of the disc. That last surgery was in December. Last month I tore my achilles tendon, and required surgery on my ankle. I am in a cast, and not allowed to put any weight on my left foot at all for 6 weeks. So, I have been using crutches and a wheelchair. However, since I have been using the crutches, I herniated another disc on the side with good foot that I have been hopping on. My surgeon told me that some people have a heridetary predisposition to weak discs. After having surgery, it really requires some life style changes. I have had a very difficult time of that. I am a go getter, and want to be totally independant. I think now that I have my 4th. herniation, I am giving in and will start to ask for help. It is all very discuraging. However, there are those people who have had a discectomy, and are better than ever. I hope you are one of those people. But trust me, be careful for at least several months.
The other thing you mentioned is sitting for a long time at the graduation. My daughter gets married in June, and I am hoping I will be there pain free. I know how it feels to have that fear. But, suggestions that I have learned about sitting. Constantly get up and change positions, and also chairs. If you are sitting on the sofa, get up after an hour and move to another chair. If you are at the graduation, at least every hour, get up and go to the ladies room, or just somewhere where you can stand and walk for a little while. Another suggestion. When I sit on bleachers, or somewhere where there is not a back on the chair, I have my husband sit directly behind me. I use his legs as a backrest. It really helps. I also have inflatable pillows. I use them, and inflate them to the firmness I need. That helps also.
I'm sorry to say that you may have to make some life style changes. But trust me, you do finally give in to the changes even though it is extremely difficult. It has taken me 5 years, to get the concept. I think I am now ready to change my habits. At least that is what I say right now! I am a very stubborn person, but that's what keeps my chin up!
Good Luck. Feel free to email me directly if you need to vent!!