Love is something like lightning strike. Sometimes, you just dont know that you are in love. Love can makes people change, people going better, getting worse and love also is the best learning method in life.
In love, you always dont even know what is going to happens next. To be or not to be. Yes, you will always have all sort of questions running through your head for the entire relationship. As example,
'Am I doing the right thing?'
'Am I with the right person?'
'How long it gonna last?'
'Did she/he got anyone else?'
Absolutely, it is the way of nature. And no one can blame you for that. It just how you handle it. Either all those questions pass through you like wind or stuck in your head forever.
For me, I dont have any expectation for my current relationship. I dont know is it gonna work or not. I dont know either he is the one or not. I dont know either I am in the right path or in the other hand. It is very hard sometimes, how I need to deal with the environment, people thoughts, certain situations and lots more. Some part of things cant be shown up, spoken out and I have lots of heart that I have to take care with my unsatisfied emotion.
The situation will always be simple when I think I can feel the love more than pain. But positive mind cant always win. No matter how hard you try, the support of your partner to change your mind is always be the best solution.
In fact, what happened to you will create the NEW YOU. Mean, dont care if your love died along with your dead gf, no matter you have the bad childhood memories watching your mom has been beaten up by your dad, or you are in love with a married man, or your are in love with the same gender, all of that will make you stronger and learn a lot of things in life. It will turn you to be someone who appreciated the love more than ever. Will turn you to be more respect to other people. Will turn you into someone who doesnt want to treat others like what you saw in your life.
Go out there and be open for everything that gonna happen in your life. Keep moving on and be ready in any way of circumstances. If you think you need to fight for the one you love, just go ahead. If you think you need to push yourself harder to be better than his/her current gf/bf/husband/wife, just do it. If it meant to be, it will be always meant to be.
Either you are with the right or wrong person right now, believe that there are someone out there for you either you realize or not. If the best person you ever meet been taken away from you, maybe you are not good enough to deserve it. If you are leaving some one after you did all the best you can, means your other half dont deserve you. IF the feelings are not there, let it go. There is no used in trying if the pieces dont fit anymore.