Hey there BeauT30,
Thanks for using Apple Support Communities. We understand you're having an issue with messages and Personal Hotspot on your iPhone. Is that correct? It sounds as if you may have set up an additional cellular plan on your iPhone using eSIM as well. Dual SIM with a nano-SIM and an eSIM allow you to use two separate cellular plans with two separate telephone numbers. You can use one for voice and the other for data, for instance. Read more about it here: Using Dual SIM with an eSIM (There is a section, "Use two phone numbers for calls, messages, and data," that goes into how Dual SIM work with messages.)
Personal Hotspot is at the discretion of your cellular carrier. Depending on which telephone line you'd like to use it on, contact your carrier to make sure that you can use Personal Hotspot with your plan: How to set up a Personal Hotspot on your iPhone or iPad
This should help. Let us know if you have any questions.
Kind regards.