Answers
I feel worthless and I hate how I look.
Your value was set by two acts you had no part in: you were made deliberately, and you were bought at a price that tells you what the buyer thought you were worth. Neither of those can be revised by a mirror, a comment or a number. Comparison is the thief here — Paul says that measuring yourself by other people is simply not wise, and the arithmetic never ends because there is always another row.
Go and see for yourself
I will praise thee; for I am fearfully and wonderfully made: marvellous are thy works; and that my soul knoweth right well.
Psalm 139:14
For ye are bought with a price: therefore glorify God in your body, and in your spirit, which are God's.
1 Corinthians 6:20
For we dare not make ourselves of the number, or compare ourselves with some that commend themselves: but they measuring themselves by themselves, and comparing themselves among themselves, are not wise.
2 Corinthians 10:12