It sounds like you must have gotten your FHA loan fairly recently if it has lifetime mortgage insurance. Which means today's mortgage rates may not be lower than the rate you have. However, mortgage insurance is expensive, and home values have increased a great deal in many areas. You may have enough equity to refinance and dump your insurance, or at least get a non-government loan with cheaper mortgage insurance that will eventually drop off.
There are several ways to estimate your home value. This article covers them. https://themortgagereports.com/22633/whats-my-house-worth-4-ways-to-find-out
Then, contact several lenders and see who is willing to give you the best refinance, including costs, interest and (if needed) mortgage insurance. That is easy to do right here at The Mortgage Reports. Good luck and thank you for your question.