LP gain/loss is determined by the following:
- Your MMR relative to your rank. If your MMR is higher than expected for your rank, you gain more, and vice versa.
- Your MMR relative to the average MMR of the game. If your MMR is lower than the average MMR of the game, you gain more, and vice versa.
- Volatility - how many games you've played, which is a metric of how confident the system is in your current rating. Fewer games played means more more volatility which means more gains and more losses.
Op.gg provides incomplete or possibly inaccurate information, so we can't know for sure. However, it looks like the average MMR of your games is Gold 4 - Gold 2. Since you're Gold 1, the culprit is most likely #1 above, your MMR is lower than expected for your rank.
Edit:
That being said, this early in the season, your rank doesn't really matter. What matters is your MMR. Where your MMR goes, your rank will follow, to the point here if you go on long enough win streaks you'll even skip divisions. It's best to not even think about your rank, other than towards the end of the season where you may be thinking of grinding it out to get one more tier up, like Platinum to Diamond for example.