I have had some experience in the same things, and I would like to give you my advice from what I have had to face myself.
I am 20 years old, I am currently discerning the Priesthood and I have personally faced more attacks on me than I have ever heard of a person my age facing. Let me say this, WE ARE AT WAR!
First thing that I'd like to say is this, a spiritual attack is something that is spiritual, it is not a physical attack that can take place in some situations when you are viewed as a "Danger" to Satan's work. Limiting T.V and Computer time would be nice, but remember this, this is Spiritual not Physical. It is true that these can have some affect on your overall being but the biggest problem is that it may be a showing of the weakening of the mind.
We must grow all three, mind, body and soul. It is all three towers that fortify our castle, our holy temple that houses the most high God. In this we must not spend to much time in just our spiritual studies (Mind), but also have to stay in prayer (Soul) and the overcoming of our personal sins, these are our outward sins (Body). If you are thinking thoughts that are not your own, you are under spiritual attack, let me make that clear now. You need to focus more on your spiritual studies, looking to spending 30 min to 1 hr in personal study of the word. You can do this daily, if you wish, I would say do it 3 times a week and contemplation and meditation on yourself, and on God most importantly the other 2 days.
Remember your prayers and know that God is with you. Find yourself one phrase that hails Christ as King and makes him sovereign over you. If you begin to think those evil thoughts, you need to jump IMMEDIATELY into prayer. I usually like to pray "Begone oh ye of Evil for Christ, my Lord, is King"
Only through the name of Jesus through the declaration of the eternal sovereign God over you does the Devil flee. It is only through him, that we are free of the oppressions of demons upon us.
Listen to music, not the trash this world has dug up, but Christian music. Another thing to realize is that Music opens the soul to a wide variety of feelings. Christian music will open the soul to allow the Holy Spirit to work more deeply inside of you. The same goes on the opposite end for more worldly music. With this music these days, it can open channels of anger and negative emotions that Satan can use against you.
Focus on several channels that allow God's Glory to shine. I'm not talking T.V I'm talking in your meditations and contemplations on God. I view this time as a time when we can best see God, through his work in our lives and also what he has done for us. If Satan is trying to make you feel worthless, then say "yes, yes I am, for I am unworthy to receive the graces and mercy given to me by Christ, but through his Love I am made worthy, through his sacrifice I am made holy and blameless before the Father in heaven, I AM a child of the living God."
This is a declaration of your humbleness to God, is allows to show Christ's supreme work in your life and that your are Not of this World, but are of the Kingdom of Heaven. That you ARE a child of God.
Satan likes to use our greatest fears against us. He knows I hate the dark, I can't stand it, it scares me. I pray in the Dark, cause I know that I pray in uncomfortable settings that allow me to demonstrate that I trust God. That which is my greatest fear is my greatest weakness. That which is my greatest weakness is my greatest Strength through Christ.
Another thing that a lot of people don't pay attention to is that we must focus on Christ, call to our Guardian Angel, Look to St. Michael and also lift our prayers for the intercession of the Saints.
Christ was right, we can't do this alone, it is through him that we find our peace and through him our strength. We cannot do this alone, and thus we must call unto heaven for assistance.