Another prolapsed disc?

[Inintaice]

Hi all!

Bit of info - I'm 19, female, overweight and currently at uni - so nothing too strenuous really!
About a year ago (feb) I suffered a prolapsed disc. I originally did it and had pain, which I coped with just about until I picked up a heavy bad and presumably did more damage, resulting in hefty painkillers and a few months of physio. At the time, although I didn't have much back pain, I had terrible sciatica in my right leg, no relfexes in my ankle or knee, loss of feeling in my foot and could bend over at all (not even to put socks on!) and after 4 months of physio everything was much better.
Over the next year or so, sometimes I would get a sore back and I didn't really think much of it. Then a couple of weekends ago a had quite mild pain down my left leg but after a day, it went away.
Then on Saturday, after meeting a friend for coffee, I got out of the car and could hardly walk. I had terrible pain in my back and even tilting my pevis forward the slightest bit was agony. I was limping quite a lot, because putting any weight on my right leg was making the back pain even worse, even though i had no sciatica.
It's now thursday and things are pretty much still the same. I don't think I have sciatica - it's quite hard to tell where the pain actually stops - but the back pain isnt nice. It's really bad if I tilt my pelives forward - sort of streching my back, and the pain seems to be a bit higher than when i had the prolapsed disc. I can't sleep that well because every time I roll over it hurts. Also, as soon as I get up I find it hard to put any weight on the leg, but after a few steps it's much better.
Oh, and also, not sure if its connected, but when I was walking yesterday, when i put weight on my leg, my back would sort of click - not properly - the sort where only you can feel/hear it - probably just feel. More like a very faint grinding.
Just not sure what to do really. I'm taking pain killers, but was wondering whether this could be another slipped disc? Or something else?

Any ideas?

Thanks