I do suffer from comparison, so I empathize. I’ll also say that it is very possible her life is “perfect”. However ultimately that has no relevance to you. You have to unfollow and also block her on Instagram. I also know it’s easy to just unblock someone. But you can think, “I’ve come so far. I can’t unblock her now.”
Comparison is the thief of joy. Why are you letting her occupy your brain space when she isn’t thinking about you? You can’t compare someone’s best to your worst.
And lastly try to cultivate gratitude.