Dee Dee,
The following is only my experience and belief. I'm not "preaching" or giving you direction by any means.
Only the Holy Spirit knows your situation fully.
If you feel like you are being attacked by evil forces, then you probably are.
In my experience, only a very mature Believer will understand your experience.
It could also be physical. Depression can have physical causes and require moderate medical treatment.
I suffer from depression and my physician is a Christian.
Also, college is stressful. I completed my Masters in Engineering at age 41, so I understand.
You know that you are in God's Divine Will if you really want to complete your training to help others first, then trust God for meeting your material needs (wages). Being a nurse is like directly assisting Christ, the Divine Healer.
When I fully submitted to God a few years ago, my life changed. I was less focused upon myself and more focused on God through Iesous Christous and the Holy Spirit. I was able to conquer alcoholism, nicotine, and drugs with the help of Christ and the Holy Spirit. But I had to totally submit and that required some seemingly great losses in life. However, now I know that all things worked out for the very best.
Even those who are Christian psychologists may not believe in the power of the evil one.
Since I have a very scientific philosophy, I never would have believed in demonic forces unless they were experienced firsthand...which they were.
I am Orthodox and Coptic, but if you are Protestant, there are some excellent works by a Minister from around 1900, named Andrew Murray. His book "Absolute Surrender" and "The Power of the Blood of Christ" can really help your faith. Even when you are standing in line at the grocery store, get into the habit of saying mental praise to God, like "I trust in Thee alone, Lord". Brother Lawrence, a Roman Catholic Monk, performed these mental prayers during all mundane work.
Also, realize that we are living in a time of great upheaval worldwide with the Christian Faith under possibly the greatest attack since pagan Rome was in power. The battle requires strength, and strength is built through exercise: heart mind soul strength.
Please read Psalm 62 and really focus on the "God alone" phrases.
God is ALWAYS good and wants what is best for you, even if you cannot see it at this point in life.
Have faith: God will be with you.
I hope this helps a little.
In the Holy Name of Christ the Most Glorious King,
Orthodox