Hi LockedShut. I'm so sorry you are feeling this way. I cried when I read your post.
First, how long have you been on the meds? Sometimes it takes a while before they start to work. If you have been on them a while and they are not working you need to see a Doctor who will try something else. You do not have to see your regular Doctor if you feel they are unsympathetic or difficult to talk to.
You are not worthless, pathetic or a push over (or any of the other things you say about yourself). You are just as valid and special as anybody else. You will have a husband and children one day and they will not get your depression. They will love you because you are special.
You are only young, and it is normal to be confused about relationships at your age. Just be kind and truthful to your friend and everything will work out in the end.
You are thinking negative dark thoughts because you are unwell. There must be someone you can confide in. There is no shame in feeling the way you do so please be honest so they can help and support you.
You are poorly at the moment sweetheart, but things will get better, and you can achieve anything you want. Just concentrate on getting better for now, and take one day at a time.
Please PM me if you need to talk.
Love and big hugs from shoegal xxx