Question for UK members about Employment and Support Allowance.

I am not really sure where else I can ask this, so if I am in the wrong place I am really sorry, but I am a bit confused about my benefits and was hoping someone could help me out!

I have passed the 13 weeks assessment period and it was apparently deemed that I do qualify for the full benefits in the work related activity group. I was informed of this by my advisor, but I was never asked to attend the medical assessment, my advisor said I was probably passed anyway as my reason for claiming is due to surgery on my spine (not really something that can be faked). My question is though, now that I have technically passed (or failed, depending on the way you look at it) the medical assessment and am in the post-14 weeks payment, along with work focused interviews and so on...do I still need to provide a sick note from my GP every 4 weeks?? I can't find information regarding this, but as I am recovering my doctor is understandably wanting to encourage me back to work, and I am wanting to find work as soon as possible, but I am terrified that if my GP stops giving me the notes, even though I still would really benefit from the support that is being offered to me through ESA, that they will just throw me back on to Job Seekers Allowance and I will not receive any support with regards to my health and struggle more than ever to find work!

I really hope someone can help me out with this....again, I am sorry if this is in the wrong place, but I have used these forums over the past few months and have really found everyone to be very helpful, and couldn't think where else to turn!