Beginners FAQ on sausage making, meat curing etc may often be found at the head of each relevant section, but here is the place to ask experienced users for advice if you are still stuck or need more information...we're here to help!
I'm a bit of a beginner myself, but I think I have a little experience that applies here. The first couple of times I made smoked kielbasa, I used collagen casings and had a similar problem. It turned out that they're not the right tool for the job. Switching to natural casings did the trick.
I have made many hot smoked sausages with collagen casings, and have never had a problem. My casings were intended for regular fresh sausage, and I have never had tough ones.