Solidworks is a great tool when it comes to 3D modeling the injection mold tool cavities and the product itself, but may not be the best option when it comes to simulating mold filling, cooling, and ejection.
If cost and learning curve aren’t an issue, I’d recommend Siemens NX for an all-in-one solution. NX is great when it comes to modeling mold-specific features like automated parting line creation, advanced cooling channel design, and integrated mold flow analysis. If you’re working with tight tolerances and complex mechanisms, NX offers better capabilities than SolidWorks.

If you’re looking for analysis tools to complement SolidWorks, however, Moldflow is a great choice. It isn’t really a CAD tool but is great for optimizing cooling, gate placement, and warpage analysis. You can use it alongside your existing SolidWorks models to validate your mold design before manufacturing.
Another option is Creo. It has a dedicated mold design module that can handle side actions and complex parting surfaces well. It’s a solid alternative to NX if you’re looking for a balance between power and usability.