I know that feeling bro. Stay strong. Let me share some advice: You're overthinking the problem and that is bad. Because of that you will walk in circles on and on until someone give to you something new to you worry about. That's not the solution. Let's go to the basic, how many girls are there? I'm talking about numbers, real numbers. Do they always think the same about you? That's impossible. Mostly of people disagree about, politics, lifestyle and even food. But you're the only one that every girl in the PLANET has common ground? Nope. Who said to you that women needs experience? That's the point that I think is hurting you more. What is that "expirience" exactly? Know how to go to the movies? I think you have done this at least once in you lifetime ( if not, do it now!). Know how to kiss? Every girls has their on rhythm of kissing, you are going to learning thought the time with her and if you meet a new one you have to start over again. Know how to fuck? Have ever read how many married people, I said MARRIED PEOPLE, is unhappy with their sexual life? Experience is not same as the willing to do it right or have intimate connection with someone.
About dealing thugs having the girls, I repeat, how many of then? All the women in the world? The Queen of England? Who they are? Strippers? Yeah, so in this case is not because he has "experience" or even looking, it's because of their profession.
it's the fact even if it did happen now it's almost guaranteed to be a girl that gave her best (when she was young) years to someone else." Who told you that? Because, I see Scarlet Johansson now and I still think she is her best years (30 years old) and Monica Bellucci also ( 50 years old).
See, if you are having some doubt about you capacity or looking how about "reality check it"? Ask yourself, "is there any data that support what I'm thinking OUTSIDE of my own life?".
About couples. Yeah, it sucks! See everyone cuddling, and hugging make you feel more alone. But this feeling is involuntary and even irrational. Imagine that you are in a road going to New York and see a plate to New Jersey. You have been there and you know where Shopping malls are and even where to find a delicious pizza or when you lost your wallet in the subway. But you must go to New York, so you keep going besides every plate showing that the turn to New Jersey is a few Miles away. Is the same in the situation of seen couples in public, you mind is going to a place and see that "plate" in the couple's faces and trying to bring a lot of good or bad memories about that. Do you know what you must do? Keep going to New York.
Summarise: Check the data before think about it. "Is there any real information about what I'm thinking is true?" Keep going to New York. Ignore the plates that will fool your route