I'm so sorry you're going through a rough time. It can be such a painful thing when the person you love no longer wants to be with you.
I know it feels like it but I hope you will re-think the idea that you NEED to be married. I feel it might be better to think that you would 'prefer' to be married.
It seems to me that depending on another person for your personal happiness is a risky business, y'know?
Perhaps if you don't feel like socializing yet you could start with taking care of yourself. Maybe you could focus on pampering yourself a little at first ... take long hot baths, drink cups of tea ... try green tea so good for you and full of anti-oxidants.
Maybe you could start doing a little light exercise ... just a little stretching in the morning, a little 5 minute walk whenver it's warm enough. I know it seems simple and obvious but it sounds as though you need to get back to basics. Watch movies that make you happy or entertaining television shows that make you laugh.
Believe me you are not too old and you have the power to create a lovely life!
Keep posting ... this is such a great place for support and the kindess of strangers has helped me so much since I joined myself. Sometimes it's just nice to know you always have a place to vent!
Hang in there :) Post often