Imagine how you'd feel if your dream girl said she might "settle" for you. She had someone better in mind, but he was out of reach, so with reluctance she decided you'd have to do. Belittled? Inadequate? Pathetic? Don't do that to someone else.
OK, so you want this ideal girl? Chances are she probably isn't the one you think she is -- but that doesn't mean the journey is pointless. It could be the wake-up call you need.
One of the wonderful and horrendously unfair things about being a man is you have huge opportunity to increase your own attractiveness. Whilst women tend to be judged more by their looks, men tend to be judged more by who and what they are. That's good news for you, especially with your current attitude -- the scope for improvement is likely massive.
Firstly, forget about chasing women. They don't find desperation attractive, and you need your concentration elsewhere. Notice the most attractive guys rarely if ever chase. Notice the least attractive are whiny, clingy and fawning. Don't be one of them.
Now you need to craft a personal mission to improve yourself. This will be deeply personal to you, but generally you'll want to make the most of your health, wealth, appearance, social awareness and develop a broad range of interests and skills. This is not a 20-minute exercise, and if you need one of those, you probably should go back to feeling miserable.
-Volunteer: give blood, teach, build a shelter
-Take a dance class
-Learn to cook
-Travel somewhere life-altering
-Take up a sport and get good at it
-Join a book club
-Learn about body language and human psychology
-Seek out the best media -- music, film, books -- and develop a deep understanding of them
-Learn a magic trick
-Start a company
-Try public speaking
-Learn to dress well
-Raise money for a good cause
-Start a creative project -- like a short film, a single or a short story
-Get a coach to help you
-Learn a musical instrument
-Make a crap-ton of money
-Run a marathon
Do something to inspire others. Do something to inspire yourself. You'll quite literally be a better person, and a damn sight more attractive. Your life should be a testament to greatness, not a self-piteous whine.
Chances are your ideal girl really isn't. It sounds like you're so attached to her as an ideal you can't see her as a person anymore, and clinging on to that thought is only making you depressed. You need to direct those energies elsewhere.
You and you alone hold the power to turn it around and make something more of yourself. Your life is your story to write -- and the hero always gets the girl.