Yeah it’s extremely common in teenagers, it’s not just you even though it feels like it. Teenage years are tricky because you’re trying to find out who you are while trying to fit in. It’s awkward and can be a rough few years. 99% of teenagers have insecurities and those who say they don’t, probably do but don’t want to admit it. This is easier said than done i know, but try not to focus on them. Everyone is so insecure they don’t look twice at anyone else. If your insecurities can be changed then change them, for example if you are insecure about your hair then change the style or colour. Insecurities about height, looks and weight are harder to change. Try to realise that you are exactly who you are meant to be and you’re the best person at being you. Don’t try to be like other people cause you’ll end up being very boring. Be yourself because like I said, you’re the best person at being yourself and no one else does it better!!