I'm not handsome, and that really makes me sad. Tell me something that convince me to stop thinking about that.

All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger. 

A believer should not be concerned due to lack of his good complexion. Many good-looking people suffer from a bad heart and many unattractive persons have a good heart.

The Prophet said: “Allah does not look at your bodies nor your appearance but He does look at you hearts.” [Muslim]

The Prophetic Hadith indicates that faces are regarded by creatures while the hearts are considered seriously by the Creator. So, don't worry about what people think rather care about what the Lord of people regards.

Know that giving importance to such matters is due to decrease in having faith in predestination that is compulsory and a pillar of faith.

It is reported in 'Sunan At-Tirmithi' that the Prophet said: “One among you is not considered a believer till he believes in al-Qadar, good and bad, and until he believes that which has befallen him was not going to pass him by and what has passed him by was not going to befall him.”

Note that Allah Subhana Wa Ta'la has been bestowing upon you uncountable blessings. So, you have to be thankful for those blessings. The foremost and important grace is that He guided you to the true faith. Only by true faith one may enter the Paradise and avoid the Hell.

Know that good health is also among the many blessings; many people suffer too much from bad health.

There are many more blessings you may ponder such as the sense of seeing, hearing and power of talking, etc. So, one should take the opportunity of his life before his death, make up for the past sins and negligence, and ask forgiveness for his shortcomings. It is narrated in 'Sunan At-Tirmithi' that the Prophet said: “Part of the happiness of a son of Adam consists in his pleasure with what Allah has decreed for him, part of the misery of a son of Adam lies in neglecting seeking the Divine Guidance in all his concerns, and part of his misery also consists in his displeasure with what Allah had decreed for him.”

Therefore, repent towards Allah for objecting to Allah's fate and divine decree. Know that Allah may inflict upon you any misfortune and trials that may remove your past memory. So, ask His blessings He is full of Bounty to His creatures; no one can prevent what He grants; no one can give what He prevents and no one can resist what He decrees. So, engage yourself in reciting the Qur'an. Allah will dispel your grieves, increase your faith and bring you happiness and stability. Allah says: {O mankind! There has come to you a good advice from your Lord (i.e. the Qur'an, ordering all that is good and forbidding all that is evil), and a healing for that (disease of ignorance, doubt, hypocrisy and differences, etc.) in your breasts, - a guidance and a mercy (explaining lawful and unlawful things, etc.) for the believers.} [Quran 10:57]

Allah knows best.