There is nothing wrong with you and please don't hate yourself. I know I could often found many better things to do than study, but it's best to exercise self control, switch your phone off and put it out of sight.
You are created in the image of God and Jesus came to restore you back to God, don't believe anything different about yourself. God loves you and He proved His love by sending His only Son, see 1John 4:9.
Please watch some Dan Mohler to encourage you:
Great response David! Amen and Amen.
Jie . Zel, it will come down to you making a choice. Try to think of using your phone as a reward for getting your work done. We all have temptations. Satan is deceptive and pervasive...he will tempt you to avoid the things that are good for you. We can't overcome in our own strength. A few scriptures to think of are as follows:
"No temptation has overtaken you but such as is common to man; and God is faithful, who will not allow you to be tempted beyond what you are able, but with the temptation will provide the way of escape also, so that you will be able to endure it." 1 Corinthians 10:13
"I can do all things through Him who strengthens me." Philippians 4:13
Being tempted is not a sin, it's how we respond to those temptations.
Praying something like "Heavenly Father, I'm being tempted to _______________________, I know this is not what you would want for me. I'm grateful that You understand everything that I'm going through. Thank you Father for always giving me Your best. Help me to make choices that will allow me to live in to the purpose and plan you have for my life. Please keep me on the path to making choices that will honor You, reflect Your love, forgiveness, strength and glory in my life. Thank you for loving me and guiding me. Thank you for the truth that I can do all things through You, because You give me strength, I can't do it without You. Please forgive me when I fail, thank you for Your Grace and forgiveness. In Jesus' name. Amen."
Also remember, Not every temptation comes from satan... sometimes it's just our fallen human disposition.
See Romans 7:15.
But also remember 2 Corinthians 5:17.