HI ellen,
sorry to hear that your parents are separated and you’re having a hard time. Im not sure how if a certain incident made you feel this way or if it was a series of events that led you to feeling lost. the time we spend between the age of 15-30 is riddled with problems and confusions so you’re definitely not alone. Having said that – happiness and depression, success and failiure are transient and cyclical in nature. nothing stays constant – therefore this feeling of being lost will pass 🙂

I would suggest that you do take measures to be proactive about finding purpose and seeking happiness – start with small things. make a list of interests and things that make you feel happy and good about yourself – they don’t have to be big things – it can be small things like – the smell of fresh grass, or hot coffee or even taking a walk by yourself in the sun or just watching some feel good movies. ( these seem small but you can expand from there – baby steps ! )

It might help to make a list of all the good memories you have and recall them in as much detail as you can – our minds doesnt discriminate between real and synthesized experiences. if thinking about something positive from the past makes you happy then you will be in a better state of mind – almost as if you have just experienced it.

once you are in a better state of mind you will be in a better position to deal with the challenges of your life. I used to think that happiness, purpose and direction are unrelated things and are external phenomenon but ive come to realize through personal experience that happiness and security come from within. if you practice positive thinking – and you have to keep at it – things will turnaround and you will be able to find the solutions to your own problems. being in a negative state of mind attracts more negative people and feelings of uselessness into you life. The best think to do is to work on being a happier you 🙂

here is some fun reading –

http://www.hungryforchange.tv/article/22-habits-of-happy-people

hope this helped 🙂 and hang in there <3