You need a break, maybe drop the weights completely for about 2 weeks and give your joints a rest. Cut out the running and just play rugby. After 2 weeks off ease back into training over the next 2 weeks and maybe tone it down a bit. I know it sounds bad but you seem to be slowly breaking down from over work. Also throw in A LOT of fish oil too its a great anti-inflammatory and good for your overworked joints.
How far are you running too, being a big guy can be hell on your legs. I find my calves give out quicker as I get bigger (92kg vs 105kg) so either cut down to short and medium sprints (more important for rugby anyways) or you will need to drop some weight.