Thanks to openstreetmap, suggested by AdamB, I have successfully found a good circular route now which will get me through to the end of the 9 weeks. It's along the canal still, but turning off just before Carpenters Road into the Olympic Park (first time I've been in) up another river, across a bridge, down a third river, then back to the canal along the Greenway. It gave me loads of long stretches to get into the running, more scenery to look at, and fewer people (the park was deserted!) - also really knowing that the route is long, and that there's room to expand into, so to speak, helps me to really push at the end.
I also adjusted my technique. I am now starting my runs really slowly for about the first 10 mins, then speeding up. When I say really slowly I mean a sort of slow jog, barely faster than walking pace. This helps me to get a rhythm, mostly helping my breathing, and then after 10 minutes I start to speed up. (Whereas before I was getting tired too early and having to go slower and slower). Today at 5 mins before the end when Laura suggested speeding up if I wasn't too tired, I sped up a bit more and it felt really good.
I'm mega pleased with my new route - does the technique sound good too? It feels like I've got a chance to really improve my technique now, and get some speed going as well as endurance, although being careful too, last thing I want is a bad run or an injury at this point.