Hi there. Listen, usually medication takes at least one month to really start working and as far as I remember you have not been taking it for more than a month, so please be patient ok?
About your therapy, I think it would be a lot better if you could see your therapyst at least one a week. Also, you can call him to let him know how you are feeling and he can give you an "emergency" appointment.
About life´s meaning or purpose I can recommend an excelent book (though I don´t really know if you are a reading lover.. I hope so...)
It´s called "man´s seach for meaning" by Viktor Frankl. It´s a book written by a very famous psychiatrist who had the same question you had while he was trying to survive the death camps from the germans.
Also, if you want to talk about something specific please, don´t hesitate to write to me please! Maybe I can help you somehow...
Big hug and I hope you feel better...
Lucia