I was you once. Exactly you. Family life and all. On medication, in group therapy... None of it seemed to work. And, like you, I wanted to give up. And tried, more than once.
But, you have to understand that it does get better. If I could go back and talk to myself as a teenager, I'd let her know that it's not hopeless. Things do get better, if you let them, and if you're willing to work for it. It took me years, YEARS, to learn how to be happy. But, I did it. You can do it, too.
Start by going to a therapist who will see only you. Group might not be working because you need someone who will focus only on you. I never liked having to wait my turn, or having to talk about my problems in front of other people. Once I got into one-on-one therapy, I could really start working on it.
But, unfortunately, for a long time I was sort of trying to stay depressed. I was at once afraid of being "normal," and afraid that I wouldn't like the person I became once I got better. But, I worked hard, and now I'm great. Life is fantastic, and even if it does get boring sometimes, I love it.
You really need to try a different medication, too. Some people have to go through quite a few before they land on the one that works best for them. Prozac is obviously not working for you. So, talk to whomever prescribes it, and ask to try another. Keep trying until one works.
Don't give up. It might seem easy to give up, but it's not. And it's not worth it, either. You get one life, so you have to work hard to make that life good. If you end it now, you don't get another try. That's it. There's nothing after that. You don't want death. Death is oblivion. Death is nothing. You want relief, and I'm sorry to tell you, but relief takes work.
I'm sorry if any of this offends you. I read your post and I got a clear image of my teenage self in my head. This is everything I wish someone else would have told me back then. Or, maybe they did, and I just didn't want to listen. Please listen. People care about you. Your life matters. Your existence has a point, you just haven't found it yet. Keep looking. Never give up.