Finish each day and be done with it. You have done what you could. Some blunders and absurdities no doubt crept in; forget them as soon as you can. Tomorrow is a new day; begin it well and serenely and with too high a spirit to be cumbered with your old nonsense.
Life is too short to wake up in the morning with regrets. So love the people who treat you right, forget about the ones who don't and believe that everything happens for a reason. If you get a chance, take it. If it changes your life, let it. Nobody said that it'd be easy, they just promised it would be worth it.