We understand your struggle with finding happiness only in personal success and the envy that comes when seeing good things happen to others. We commend you for recognizing the need for a change of heart and turning to God for help. The Bible tells us in Proverbs 14:30 WEB, "A tranquil heart is life to the body, but envy rots the bones." Envy is indeed destructive, and it's commendable that you seek to overcome this.
God calls us to rejoice with those who rejoice and weep with those who weep, as written in Romans 12:15 WEB. This is a mark of true love and compassion, and it's what God enables us to do when we yield to His Holy Spirit. Remember, God is the one who gives us the power to love and be joyful, even in difficult circumstances. As it is written in Philippians 4:11-13 WEB, "I have learned in whatever state I am, to be content in it. I know how to be humbled, and I know also how to abound. In everything and in all things I have learned the secret both to be filled and to be hungry, both to abound and to be in need. I can do all things through Christ who strengthens me."
It's also important to remember that our joy and contentment should not be based on our circumstances or successes, but rather on our relationship with God. As Jesus said in John 15:11 WEB, "I have spoken these things to you, that my joy may remain in you, and that your joy may be made full."
To have a tender heart that mourns with others and does not exaggerate our own problems, we need to put off the old self and put on the new self, which is renewed in knowledge after the image of its creator, as it is in Colossians 3:10 WEB. This means allowing the Holy Spirit to mold us like clay, as you've mentioned.
Let's pray together:
"Father, we come before you in Jesus' name, asking for a change of heart for the one who has requested this prayer. Help them to find their joy and contentment in you, and not in personal success. Give them a spirit of love and compassion, that they may rejoice with those who rejoice and mourn with those who mourn. Help them to put off envy and put on the new self, renewed in knowledge after your image. Mold them like clay, that they may be conformed to the image of your Son. In Jesus' name, we pray and ask humbly, amen and amen."
We encourage you to continue to meditate on these scriptures and ask the Holy Spirit to help you apply them to your life. Remember, it's only through Jesus Christ that we have access to God, and it's only through His strength that we can overcome these struggles. As it is written in Acts 4:12 WEB, "There is salvation in none other, for neither is there any other name under heaven, that is given among men, by which we must be saved." Keep trusting in Him, and He will give you the power to love and rejoice as He intends.
Prayer Focus: God, Thank You for loving me. God, I ask You in Jesus’ name please bless me with everything that I stand in need of and everything You want me to have. 
