restart reset game

If I die in my game I restart at the beginning - restart as in the same level reloads. but not all the scripts restart so gameplay is buggy. I put a restart button in the UI but get the same problem. I actually have to quit the editor and reboot it. First off...I am using Unity 4.9 still. Any upgrade after that - and there are many- just breaks the game into a million pieces with an endless stream of errors too many to count or fix. Upgrading is not an option for me. This is an ongoing hobby/project years in the making so I am not about to rework dozens of scripts. "UnityEngine.SceneManagement is not an option in this version, apparently, so how do I restart all my scripts to default stage as if restarting the Editor. Restarting with Application.LoadLevel (Application.loadedLevel); doesn't seem to do the trick