To reach higher Cps you can try various clicking techniques, holding your mouse a different way, or trying out a new mouse.
I use the "Razer Mamba Elite", and it works good for me, even after years of usage. The only bad thing about it is that you can not drag click very well.
I had a cheap 15 euro mouse before, and it worked a lot better. The cheap mouse is from the company "Tecknet" and is called "Raptor"
Then there is a mouse which I heard was one of the best for drag clicking. The company was bankrupt once, but now it exists again. The company is called "Mad Catz" and the mouse is called "Cyborg Rat 7"
Please remember that you do not have to buy a new mouse to reach high cps.
If you decide to buy a new mouse I would suggest going to a local store, they most likely will have some mouses opened and connected in the store which you can try clicking on first.
To avoid misunderstandings I have included pictures of each mouse that I mentioned