I have had lots of sad things happening to me in the past, the biggest one being the loss of my youngest daughter about 6 years ago. She was in an accident and died when she was only 12. I still cry, feel bad, sad, etc. because of this. My oldest daughter is having a lot of problems because of this, so I am very sad and worried about her.
Does this mean I am never happy? No! There are still things happening in my live that make me happy. I learned to appreciate the small things that we normally take for granted. Just spending some time with the people I love is more important now then it was 6 years ago.
But am I happy enough and will I be in the future (as your question is)? I don’t think so. It is very sad to know in hindsight that I took the time spending with my youngest daughter for granted. I will always have to live with this fact and the fact that she is not here anymore. I will never be as happy as I was before it happend, even though I didn’t think I was that happy at that time.
My strategy for now is to just enjoy the moments I can enjoy and be sad when I need to or want to. Just take life one moment at a time. Don’t worry about the future, because there is a possibility that there is no future. Just stay in the moment and handle it as you need to. Be happy if you can, be sad if you need to. And be aware that every state you are in will change over time. If you are happy, it will change, if you are sad, it will change. You can never be happy or sad all the time.