OP, you ask a lot of really good questions. I was married and we had a son. Husband ran away from home when son was only a couple of months old. A few years later, I rekindled a friendship I had with a guy whose sister I grew up with. We were together for about 3 years when he died from brain cancer. I loved him, and he taught me what it was like to have a God-honouring and healthy relationship. Even though we had only been together for three years, losing him was the hardest thing I ever had to go through. I was devastated and I had to learn who I was without him - he was so much part of my identity, and we had an incredible spiritual connection that was broken when he died. Part of who I was died with him. I was single for the next ten years. I had no intention of ever marrying or loving anyone ever again. But after a decade, I came to see that I did not want to grow old alone. So... I found a companion and we married. Being single has one set of problems - loneliness, no sex, feeling like a fifth wheel when out with friends, finding single friends my age, etc. Lots of hard times. When I married, I traded in all those problems for a different set of problems - learning to live with someone else, tolerating their quirks, working through conflicts, navigating different opinions, values, ideas, tastes, etc. One set of problems is not more difficult than the other - they are just different. One thing I have had to learn to avoid doing is thinking of the grass being greener in the decision I did not make (ie, the grass is greener being single, when I am married).
Here is the thing. If you find someone that you are spiritually connected to, and you have a healthy relationship, that is worth every minute of grief you might have when they pass away. I have no regrets loving my deceased. I have no regrets mourning him for a decade. I have no regrets in moving on (even though this marriage is not as easy as my relationship was with my deceased).
I think what you have to figure out is whether loving another would be worth the troubles that relationships bring. And you can't do that unless it's on an individual basis. If you go about your life the way you are, and are open to marriage if the right one happens to come along, then you don't have to make this decision right now. You can be content with your singleness for now, and if you find someone you want to marry, you can also be content married.
As for the sexual temptations that come along with it, I do have to say that lust is a sin....but only you know where you are in your relationship with God, and only you can decide when that is a sin you're ready to deal with. When you are convinced that you love God more than you enjoy the occasional pleasure, that is when it will be time to deal with it. The thing is, we all still have sin even after we know that we love God more than we love pleasure of the flesh. It's why we rely on Jesus to be our salvation. I'm not saying it's a license to sin, but that you do your best to abstain and if you mess up, you know you have a Saviour who advocates on your behalf with the Father.
