There's a loose requirement for getting promoted into a new tier, but there's absolutely zero MMR requirement to stay in a division. As long as you don't lose a game at 0LP, you can stay in your division indefinitely. This means you can have Gold V (or even lower) MMR players chilling in Gold II. You also need to reach division IV MMR of the previous division to get dropped down a tier.
This means there's some serious desync between players' actual skill level (MMR) and their current rank. There's massive overlap between Silver II and Gold IV.
According to op.gg, your MMR is ~1625, which is roughly Gold III. You were 2-3 wins away from a Gold promo, you were most likely getting really good LP gains as the system tried to push you into Gold. It's unfortunate that you ran out of time. But it was due to personal reasons, not because of Riot or matchmaking. On the good side, you have a good chance of getting placed directly into Gold next season.
So you're saying that it's not harder to win against Gold Players than it is against Silver players?
The difference between high silver and low Gold is really small, if not non-existent.