Your case is not so peculiar, as this envy-feeling is really common amongst the not-so-good-looking girls/women. Looking at uglier-than-you girls would really make you feel good, or such ideas may work, but in the negative sense, in the sense, why to find ugliness in others (comparisons and evaluations are bad for mind - says psychology), as all are - including you - WHOLE, PERFECT and COMPLETE. Remember - YOU ARE VERY BEAUTIFUL. Beautiful lies in beholder's eyes. The concept of beauty differs from person to person, country to country and community to community.
Let me recall a beautiful experiment, done by Yuri Borov, a famous Russian aesthete. He got a group of randomly chosen people of different age groups, different countries and different natures, and let them be together for some days. Asking them to rate one another on socio-metric scales on beauty aspect, he assessed their views about each other, as to how much beautiful they find others. First day they gave importance to face value, but as the time passes (the SMS, I mean socio-metric scale, was given every day) they started forgetting face value... but here, I am not repeating your INSIDE BEAUTY concept, but telling about changing concept of beauty (with time, as one spends with you, and not in WHOLESOME time).
Face is not the only criteria of beauty in the world, for some it is hair, for others it is your smile, and for some, your body features and for some, something else...
For example, simply long haired girls are considered beautiful in India, but in Europe, bobbed girls or girls with short/shingled/cropped tresses are called beautiful. For Sikhs, long uncut hair are wow, but for others, trimmed locks are the ultimate concept of beauty. Some prefer shoulder cut, others very short, and some even boy cut, but believe me, there are many who even LOVE to see girls BALD. (There are many in South India). Check here, if you want - http://www.orkut.co.in/Main#Community?cmm=35239791 http://www.orkut.co.in/Main#Profile?...62970630518362 http://www.orkut.co.in/Main#Community?cmm=19802890 http://www.orkut.co.in/Main#Community?cmm=55775346
(There are many such, which you can easily find, but the point is... )
If lanky girls are liked by some people and in some communities, some prefer short-statured girls, as in China.
Remember, there is no one definition of beauty, and usually, we have our own concept of beauty and we compare ourselves with our own concept of beauty, and thereby if we fail in our own criteria, we feel ugly in our own eyes, even as for the world, you may be nothing less than Marlyn Munroe or Aishwarya Rai.
LAST - You said you cut off your hair, but it did not help you look better. Consult an expert hair stylist, about which CUT will best suit you. See me in the snap, here, and you can see how bad will I look with boycut or even a braid or knot behind (but it is my perception, or of some people) and loose dress and full sleeve garments will make me look worse, I presume. More hair on head may make me shaggy. But it is -believe me - perception of one person, that is me. For you, it can be another, for another, another.