Ok, lots of people have said and it might sound trite, but self confidence is important, in all aspects of life, including dating, I myself struggle at times with it too. However, people can pick up a confident vibe, and those that have themselves together, will sense confidence, and that can count more than anything; looks, height status or whatever else.
Dont believe everything you see online, Hollywood, porn etc, alot of it is all fakery bull@#$&.
Just work on what you do have or can bring to the table, dont worry so much about height, not all girls are obsessed with having a super tall dude, tall like a redwood tree.
5 ft 10in is fine, for instance if she wants 6ft, this to me is almost like splitting hairs, who is going to notice a two inch difference in among crowds unless she goes around with a tape measure, we are entitled to our preferences though, and I may have a bias, since I am not tall myself, so most people being taller than me, that height is plenty tall enough to me.
Just remember, looks are subjective, and a guy can seem like the best looking, pull in the women, but if he is an @#$&, his good looks are wasted, what is most important is if he treats a woman with respect and listens to her and values her.