Hello Ana,
How are you doing? I hope you aren't stressing yourself out as usual, I can tell you now, that is the most useless thing to do! I am writing because I have been thinking, worrying about you, trying to imagine what would be the best way to approach this. I am writing to calm you down and to give you a little bit of a pick me up, as well as a reprimand because not everything had to be awesome about this letter!
Life is a rollercoaster, it never ceases to be like that, even when you think you'll have it all under control you probably won't, so don't try to plan every single minute of your life. Let uncertainty become an ally and don't become uneasy just because you don't know what the future will hold, be excited about all the possibilities that it contains. Everything can change in the blink of an eye, cause and effect, and you can't do anything about it.
Enjoy the little things in life; no, this is not the typical phrase you paint on a canvas, I truly mean it, for every single thing that makes your heart flutter with joy there will be another that will crush it. Don't focus on the negative part, think about how blessed you are that you have enjoyed and will enjoy the good ones. Good things and experiences come disguised so they will seem banal, usual, even that laughter with your friends while having dinner might be taken for granted now, but I can assure you that looking back, those are the memories that stay with you and might bring a happy tear to your eye.
Give without expecting to receive and be grateful, you'll see that if you give love (most of the times) love is what you'll receive in return. Everybody needs a little bit of help and affection and while you can't do anything at a bigger scale, you can always contribute because there's already enough hatred in the world.
Smile even if you are not having the greatest of days, it is proven that it boosts your system, making it easier for you to feel a little bit happier. Whenever you think how horrible your day is, allow yourself and remember those bad times that you have already overcome and be convinced that almost everything has a solution. I am not telling you to not be sad, that is impossible, but I am reminding you that once the storm has passed the sun will shine.
Cry, let it out, cry alone or with your friends but don't let it pile up. You and I both know how hard you tried to be "strong" when you were younger, but it is healthy to let your emotions show, you are human and there is beauty in our feelings. Quoting Elsa from Frozen "let it go".
Surround yourself with people that make you a better person, people that like you for who you are, people that nurture you and vice versa. We are social beings, we enjoy sharing our time and choosing wisely.
Smile even if you are not having the greatest of days, dress up just because you want to, call that person that you wanted to hear from, travel as much as your budget allows you to, save up money for something you've always wanted to do, do some reckless (but safe) things, live like every day will be your last, savor every meal like you've been starving for weeks, allow yourself to be in awe of the wonderful things that surround you every day, live.