Cheer up, Dawi, I know the feeling too.
That reminds me of the game in 1v1v1 where my opponents did all the game in a corner, letting me hanging alone and slowly moving to them... That was... fun. ><
@Furuzzolo here made quite a good synthesis. In your case, Thunderers or Quarrelers would have done miracles I think.
20 Quarrelers, put them in Shield Wall and starts shooting while you advance. That's 40 shots screening your movement in a range of 20" and we don't care for Rend in that case. Serious threat for your opponent, Recommend. Your Quarrelers are as tanky as your fellows Warriors, remember that.
In the meantime, Pickaxe 30 sturdy warriors in their back or flank. 2nd serious threat.
If you manage to place your 1 or 2 cannons in a good firing position, that's the 3rd serious threat. I'll add that if you manage to squeeze a little Gunmaster with it in your list, Grungni may be pleased, be prepared to see flying rats everywhere. Your 1 or 2 cannons will obliterate everything within 32" range.
Don't be sad because you lost a game. Dispossessed are slow, it's true. Sometimes it will be hard to get to your opponent, sometimes you will not be in a good position. Placement and tactics are crucial with our fellow duardins. But don't give up. Learn from mistakes and see what works and what doesn't.
And for now on, you got a reason to place a grudge on those ratty-rats-rats. Next time, you'll make them pay for this insult, don't you ?