I was trying to do a portal run, then I died and later I checked the run's demos, and realized it cut off after I would have loaded the last autosave before death, how do I make it continue recording demo files after loading the save

So I am looking into speedrunning from my collection of Goldsrc mods, and was wondering what I should look to for saving time and keeping track of time, my current plan is OBS alongside LiveSplit and the goldsrc mod, but anything free and accessible (no confusing accounts stuff or user-unfriendliness) that might be better can be recommended. Thanks in advance, oh, and is there any LiveSplit addon to integrate with Goldsrc mods?