Even the handsomest gentlemen on the planet have to learn Rejection Management at some point or another. I'm sure you really don't want to hear "you're 19!", but you're 19. There are 19-year olds and young adults of every conceivable gender and sexual orientation making the same "why me?" pleas. Give yourself some time and patience. If you're anxious, it will come across in your dialogues with those who interest you, and creep people out far more than anything you might look like.
I would suggest going out and meeting people face-to-face as your primary tactic. Not being flirty, just conversing simply and naturally. When we start ALL our interpersonal connections online, we have perceived notions of what we hope the other person looks/sounds like... then the Catfishy revelations kick in and hamper what could at least have become a decent personal relationship, if not a romantic one.
Those surface-level disappointments and letdowns never get to build themselves up when you walk right up to someone and say, "Hi, I'm Brad," smiling as you shake their hand and offer up an ice-breaking conversation. Try it, and seek out common interests in things other than romance first. As a career-oriented go-getter, perhaps the nature of your career may allow itself professional networking opportunities with other unpartnered gay individuals. Or maybe your hobbies and interests outside of work may lead you to a LGBT fan club or organization of some kind. Face-to-face, in-the-flesh conversation from the jump allows the positive aspects of your personality to shine through. From your newfound friends and colleagues, you may find yourself a worthy life partner.
On the matter of building online relationships, try conversing with people who you may not think you'll have a "looks"-based romantic interest but may share something else of interest to you. The internet is all about attracting our visual senses above all others, often to our detriment when it comes to dating. Often, our first instinct is to go after all the Prince Charmings of the world, sidestepping the frogs along the path, then we think the problem is ourselves when all the Princes turn our advances down.