I completely understand where you are coming from. I have been divorced after being married for 6 years. It's difficult to be alone. There are many things that I miss and that I want in my life. However, I have come to the conclusion that I'd rather be alone than with someone that isn't right for me.
Do you have any hobbies or things that you enjoy where you might be able to meet people? It might not be the best time for it now, if you aren't in a good place emotionally, but maybe you can try dating? I think a lot of people are dealing with a similar concern - and it's important to put yourself out there.
I think it's just a normal time (in our 30s) where we start to question where we have been and where we are going. Please don't try and let it overwhelm you. You have plenty of time