Happiness does not exist outside of us.
Happiness does not come because of someone else.
Happiness does not come from a particular experience.
Happiness does not come from possessing a particular object.
Happiness is within us and is in every moment. If you cannot be happy in the now there will be no happiness.
What you are feeling is suffering from not experiencing the pleasures you desire. Pain is inevitable. Suffering is a choice. Craving and desiring pleasure leads to suffering. Believing that your life is meaningless unless you obtain something leads to suffering. That is not to say experiencing pleasure is wrong, but constantly craving it will cause mental suffering.
Find happiness in the meaning and purpose of your life. At the same time you can obtain the means to provide for yourself. Even JW parents will not object to their child pursuing the means to provide for yourself. Once you do this, by all means move out. Then you are free to do as you please.
Take some advice from an old man who was raised as one of Jehovah's Witnesses - there aren't enough drugs, alcohol, parties, and sex in the universe to satisfy craving and desire for pleasure. The real "waste of life" is failing to realize that happiness exists in every moment. That often starts with being grateful for what you do have rather than suffering mentally over what you don't have.
Do you wake up every morning in a bed inside a house with electricity and hot, running water? Be grateful.
Do you clean water to drink and food to eat? Be grateful.
Do you receive an education and have access to medical treatment? Be grateful.
The easiest way to feel better when you are feeling down is to do something for someone else. Show selfless love to others. Especially those who cannot repay you.
You are 17. Your life is just starting. I didn't get out of the Jehovah's Witness life until I was in my 30s. I don't spend time looking back at what I missed. I immerse myself in the now.
What time is it? The only correct answer to the question is "now". The past is an illusion created by the brain and the brain does a poor job at it. The future is also an illusion. Making plans for the future is pointless unless you are living in the now.