Two questions in one....

So, I've got two questions but rather than take up two threads, I figured I would just pile them in to one post. For all I know they're connected.

1-- water retention.
Most people talk about how they lose water weight on long runs/heavy training sessions, etc. I've noticed lately that my body is doing the opposite. I'm retaining it. My weight will actually go UP several pounds (sometimes up to 5 or 6) after particularly heavy sessions. I trained for my first half marathon as part of my training for sprint triathlons, and every time I would do a long run my body would bloat. And, now I've noticed it's a pretty consistent and annoying thing that happens with big sessions. It also doesn't seem to matter if I drink water, or gatorade or any combination thereof. It also doesn't appear to matter how much/little I intake either.


2-- I think I have managed to burn out my quads. I've been training pretty heavy the last week because I'm a teacher and I'm off work. But I've hit the point where yesterday I tried to run and couldn't even get through 5k and today I did a 14km bike at a gentle speed and my legs just felt exhausted. I had a rest day yesterday and all I did was yoga and walk the dogs but I'm still finding my legs are just DONE. I am worried about losing training time because my friend is excelling in her training and I seem to have hit a wall. I figured that the time off work would be helpful but my body is just having none of it. She nearly beat me in the last race we did (partly because of equipment failure -- but some of it is that I can't seem to push as hard) and at this point, I will be lucky if I can get my legs to move the way I want.

I'm curious as to how to deal with the water retention and the exhausted legs. I'm assuming some of the water retention could be inflammation?
I'd really like to push hard the next couple of weeks to improve before my next race but I'm at a loss. I struggle to stretch properly because I'm a dancer as well and hyper mobile which means that traditional stretches don't tend to work.