They always tell you to learn to love yourself before you can love anyone else. I think what a lot of us struggle with is that we put everyone else before ourselves, and then we pour our hearts out to our friends, family and loved ones. However, in the end, there's no love left for ourselves. We need to learn to love ourselves regardless of how we feel on a day-to-day basis. You might hate yourself for failing your chem final, but you have to forgive yourself. You cannot beat yourself up like that. I know, personally, I would tear myself to pieces when I embarrass myself in public or if I gain a few pounds, but I can't dwell on those situations for the rest of my life. You just have to take what you learned and move on.
It's hard to love yourself nowadays, especially with social media. You could be having the best day and then you see a picture of a Victoria's Secret model and then realize how much you need to lose weight/shape up and then you start tearing your body apart to pieces. It is extremely unhealthy to compare your body to somebody else's. Everyone's bodies work differently, and even models are sometimes insecure. I found a really interesting TED talk where Cameron Russell describes her insecurity despite her career as a supermodel. You can find this video here. Watching this video for the first time, I realized that nobody is perfect, even seemingly perfect supermodels. Everybody has their insecurities. The only way to deal with these insecurities is to love yourself unconditionally. The more you love yourself, the more you will take care of yourself, the healthier you will be, the better person you will become. It's also proven that people who have better confidence in themselves get better grades.
The past is the past for a reason. If something that happened is what's stopping you from being yourself, it's time that you let go. I try not to dwell on the past, because if I did, I would not be nearly as confident as I am today. I could remind myself of the countless wardrobe malfunctions I've had as a teenager or the time I embarrassed myself in front of a guy, but why should I care? Stuff like this happens so you can learn from it and move on. Don't ever blame yourself for the mistakes you've made in the past.
Overall, I know it's hard to love yourself with all of the pressure from social media, but nobody is perfect. We are unique individuals, each with something special that they bring to the table. If we were all the same, the world would be a pretty boring place. Just remember, don't be sorry for who you are.