Hello and welcome to CF!
It can take some time to begin to change our very thoughts and ways of being, because the enemy has been successfully tempting us in that way for a very long time. Most people have such kinds of issues, but sometimes they are not so easy to identify. Love of money or continual listing tend to be easy things for us to see in ourselves. Pride is quite common too, but can be subtle and hide so that many, many people have this as a root sin but don't even recognize it. So it's something to be thankful for that you easily know what to deal with in yourself.
Two things I could suggest (aside from the obvious ones of praying, seeking God's help, and reading Scripture.
They both have to do with cultivating a sense of thankfulness for what you DO have.
The first is to try praying like this. Once a day, pray and thank God for everything as if whatever you thank God for will be the only things you will have tomorrow. Thank God for everything you do not wish to lose. That means not only material things - do you have a home? Transportation? Food, clothing? Whatever you use to access the Internet, your phone, any treasured possessions, anything you have that is beautiful, convenience items, heat, air conditioning, running clean water, nice towels, a toothbrush, games or movies or tv you enjoy, a job, any money you have in the bank, etc, etc, etc - whatever things you appreciate. And not only that but relationships - people you care about, family, friends, pets, relationships from your past. People who have helped you in any way. Their health and safety, that God has watched out for them. And all the other things necessary to life - air, water, any aspects in which you are strong or healthy, health care, etc. Spiritual benefits - that you know God, for God's grace, the sacrifice of Christ, that God created you, that you have the privilege of being heard by God, for His love and care and faithfulness, that you have access to the Scriptures, anyone who has prayed for you or helped or advised you, that you are free to worship, your Church if you go, the help of any teachers you might have read and benefited from, etc.
Remember to try to think of EVERYTHING - the exercise is that if you forget to thank God for it, it won't exist tomorrow. Of course that isn't true, but the idea is to make yourself aware of everything you have to be thankful for. Do this for at least several days ... I would keep doing it until your thinking starts to change, which I think will not take long (less than a couple of weeks), and then continue to thank God every day by at least mentioning general categories of these things, and remember to be mindful and think of things you are thankful for, for the rest of your life.
The second is to change who you are comparing yourself to. If you live in the US, especially, we are continually tempted to compare ourselves to an affluent American ideal. There are in fact many poor people in this country, by American standards, but try comparing to the larger world population. Look into the lives, read stories and see images, of how desperately poor so many people in the world are. People who live in boxes, or makeshift houses made of gathered trash. People with no access to clean water. People without food to eat. Children losing parents due to disease and having to fend for themselves. Parents watching their children starve with nothing to feed them. People forced into slavery or an organized crime scam, or who sell their children, and so on. Educate yourself about what the AVERAGE standard of living in the world is now, not what you compare yourself to on TV. And while you're at it, if you watch shows like Extreme Pools or mansions or whatever - do yourself a favor and stop. In fact, advertising is designed to make you feel exactly as you describe, so as much as you can cut yourself off from that, the better.
Those two things should give you a more reasonable handle on what you have, and what you need, and how blessed you already are.
If there is an underlying issue of your worth, that can be worked on too. You need to learn to see how God values you, and why. Not because of anything at all you possess, but the true value is in your soul, your being a person, created in His image. That makes YOU worth more than all the wealth that ever was. The material things are all so much distraction and "stuff" that God can easily create and destroy. You yourself are the true treasure, your soul, and the soul of every person.
And I suspect it is the thoughts that come into your mind that you need to learn to recognize for what they are - a temptation to think this way, and simply let them go, without allowing yourself to interact with them. Sometimes people in our Church say - you can't stop birds from flying in the air around you, but you can keep them from building a nest in your hair. I will post a link to a podcast that might start to help - phone dying so I need to hit "post reply" now quickly, but I'll edit it in.
Here it is:
Our Thoughts, Feelings, and Memories - Speaking the Truth in Love | Ancient Faith Ministries
There are many others that can help as well.
It is something Christians have dealt with since the beginning.
I hope this is a beginning. It may be a lifelong struggle, or if you overcome this one, you may find a new one. That is the Christian life, to identify and root out such things in an attempt to cooperate with God as He transforms us by His grace to be more like Christ.
Again, welcome to CF!
