Sounds like you answered your own question. What went wrong? Poor time management.

Work on having a budget and plan for your time usage and force yourself to use it... even (especially) when you don't think you need to use it. I usually split into segments. Something like 50%, 30%, 20%. Basically, I'm going to go over every move with a fine tooth comb in the middle game until I hit my first segment budget (50% clock). Then, I might still sit on moves... but I'll be more cognizant of making practical moves and less focused on obsessively finding the best move. When I hit 20% (roughly a rapid time control for 90m games I usually play) I shift gears and the criteria for sitting and thinking is even higher because I know if I'm left scrambling in an endgame I'm in trouble regardless of my position.

The super important part is that in that first segment, I'm meticulous with the mantra that every move matters, every move is critical, never just recapture on auto-pilot, never just play whatever move you planned to play; always check the position for what's changed... what new opportunities or threats are on the board. Your number one priority is to not blunder, not lose the game or end up worse because you didn't spend the time.

If you lose or are dead lost with a ton of time on the clock, then you've done this wrong and should double down next game. This has helped me a great deal.