Five things you should stop doing

Stop begging for love or attention - I live by the principle “If they wanted to they would”. Don't form excuses for their behaviors, they show you who they are accept it and leave.
Stop going to places where you aren't invited or valued - doesn't matter how much you enjoy with them don't hang out if your presence isn't appreciated.
Stop trying to change others - that's the worst thing you can do to yourself. I will change him or her. No. You are not their mommy, invest in yourself for your goal. They are wrong, but they might be right for someone else. Find who is right for you.
Stop giving explanations - to ones who don't matter to you or will not matter in the coming years. Stop. Let them have whatever opinions they want to have about you, don't entertain them. Not worth it.
Stop putting others before you - as long as they aren't your parents or siblings. No one cares about that charity behavior when there is competition. First, save yourself then help others. This won't make you selfish at all. Show charity and a selfless attitude where it is needed. Leaving opportunities for others, umm I won't suggest. You got that opportunity because you deserve it, go and make the best out of it. And don't forget to wish good for others. Stay humble and grounded.