How to use my iPhone Internet to my computer without personal hotspot?

Sprint charges for personal hotspot and it should be free for customers that been with sprint for a long time.

Find another phone service that doesn't charge extra for personal hotspot, or get a hotspot device or a 4g USB adapter.

That can't be done unless you have a jailbreak, with a jailbreak you can install pdanet which allows you to hotspot without being charged as it tricks the phone in thinking you're using normal data.