RE: franky on your routine and overtraing
if you find that you cant do more than a couple of sets of 5 without help then you need to lower the weight. try small increases in weight like a kilo at a time. these are more manageable, motivating and less likely to contribute towards overtraining.
warm ups should be 1 set at 50-60% of your work weight and the other at 70-80%. you will find that this helps with the first set.
when you bench press you use your shoulders which would explain your performance.
as far as the forced reps are concerned i personally dont think it counts as overtraining in the strict sense but this goes back to the weight issue. if the weight is way too heavy for 5 lots of 5 then it needs to drop. if you do forced reps always its no good. i dont do forced reps for my 5X5. my sets are hard enough as they are. hth