@Kalani, complete co-sign!!! I'm glad this forum exists so that we can all learn from each other and make better life decisions. I certainly would do some things differently if I could go back in time with the knowledge I have now...
Re-quoting this part for emphasis...but I also want to add don't "waste all your pretty" on him or give one guy all of your best years, especially if you are not married to him or on the road to being married. And even then, you should still have your own interests and keep your life going. Don't make his life your whole life, if that makes sense.
To me, on the road to being married is actively planning a wedding and getting ready to walk down the aisle in a few months. Not "discussing" marriage, fake-shopping for a ring or any of the other ploys men like to use to make you think they're about that life.
Know your end game and find out what his end game is early in the game so that you can adjust quickly, change up your plays and move on if you don't share the same interests.
Doing that will prevent you from wasting a lot of time in relationships and "situationships."