I keep coming back to letter writing, the lost art form. It is rather amazing what you can accomplish by writing a letter. Nothing says, “I mean it,” more than a personal letter. Give it a shot. Take the time to craft a letter and send it to someone that helped you in a major way or someone you care about. The effort will benefit you, because you will spend focused time thinking about someone other than yourself and what you write will probably be powerful and meaningful.
The post office still exists. You can get a stamp, they are cheap and so are envelopes.
Give it a try. If you have forgotten how, you can follow these basic instructions provided by the US postal service: https://www.usps.com/ship/letters.htm