Lower back pain after two surgeries

Hi,
I have had two lower back surgeries in the past 3 months.  The first one lasted about a month when I re herniated the L4/L5 area again.  My Neuro surgeon recommended doing the same surgery again which lasted almost 3 months up until last week.  My son wanted to go for a short bike ride and I have not rode a bike since either one of my surgerys.  My surgeon said it would be ok to do so I went around the block twice with my son.  The next day I noticed severe lower back pain that continued for most of the week.  I recently got a cortison shot on Friday which helped a little yet I am still feeling pain in my left bottock area around my hip and some nerve pain in my left thigh area.  Mostly in the back and side part.  My fear is that I have done something to herinate this disc once again and I fear getting the fusion surgery due to seeing so many people who have not had success with this.  All I want to do is have a somewhat pain free life where I can do moderate things to enjoy my time with my kids.  Since I am having pain again does this mean I have herniated it again in the same area?  I know my S1/L5 disc is also degenerated and has had problems in the past but to be honest I can't tell which one is causing the pain and I am frustrated due to not really doing anything to cause this. Any advise would be great.  Thank you.

Tim