Ok, ok ok the pity party is over. Lost 10 pounds, bought some stuff and no more body pain.
First of all, I bought new shoes - Sauconys and my life is changed forever. Got them on Thursday and went to the gym and rode the bike and rowed - felt great. Then yesterday I went on a 7.5km power walk of some of the 1/2 marathon route - small blister but amazing and then this morning...10kms non stop (no 10:1s here) and did it alone and feel AMAZING.
No joint pain whatsoever.
I bought the shoes that are really good for cushioning and also stability. This has been the problem all along - my husband was right (and I never say that). I also invested in a really good sports bra - I even ran in a t-shirt today which I never do as I hate people seeing "stuff"' bouncing.
I now know that I can complete the 1/2 with less pain than last time and without doing any damage to the knees and feet.
Thank you Lennie for the advice - now will you pay for them!!!