Some slightly jumbled quotes/distillations from the last three chapters of "Spiritual Depression: Its Causes and Cure" by Martyn Lloyd-Jones. One of the most beneficial, gentle, straightforward, honest Christian books I have ever read.

When filled with worry: Come to God in prayer. First, use worship/adoration to come face-to-face with God. Second, use supplication to bring your problems to God. Then, use thanksgiving to praise God for being your Father, for loving you so much that even your hairs are numbered.
The Gospel is concerned about you, not your circumstances! God promises that “you will be kept in peace in spite of” your circumstances. He is the one who is going to do something—not you, not your prayer. This peace works by showing you Jesus Christ. God cannot forsake you!
It does not matter what you’re worrying about: “Be careful for nothing, but in everything, by prayer and supplication, with thanksgiving, let your requests be made known to God.” In everything, no matter how big or small. (“The Peace of God”, Spiritual Depression, L-J)

You are to be self-sufficient, independent, free, no matter what your circumstances. The apostle Paul was “not mastered or controlled by circumstances. By all means if you can improve your circumstances by fair and legitimate means, do so; but if you cannot, and if you have to remain in a trying and difficult position, do not be mastered by it, do not let it get you down, do not let it control you, do not let it determine your misery or your joy.”
I do not depend for my happiness upon what is happening to me.
Remember these steps:
Conditions are always changing, therefore I must obviously not be dependent upon conditions.
What matters supremely and vitally is my soul and my relationship to God. That is the first thing.
God is concerned about me as my Father, and nothing happens to me apart from God. Even the hairs of my head are numbered. Do not forget that!
God’s will and God’s ways are a great mystery, but I know that whatever He wills or permits is of necessity for my good.
Every situation in life is the unfolding of some manifestation of God’s love and goodness. Therefore my business is to look for this peculiar manifestation of God’s goodness and kindness and to be prepared for surprises and blessings because ‘His ways are not my ways, neither His thoughts my thoughts.’ Paul was taught through physical weakness God’s grace.
I must regard circumstances not in and of themselves but as part of God’s dealings with me in the work of perfecting my soul.
Whatever my condition may be at this present moment, they are only temporary, and they can never rob me of the joy and the glory that ultimately await me with Christ.
Learn to find your pleasure and satisfaction in Christ. (“Learning To Be Content”, Spiritual Depression, L-J)

Christ is all-sufficient for every circumstance, for every eventuality and possibility. A mighty power enters into us; it is a life that is pulsating in us. It is an activity, and an activity on the part of God. God is doing something in and through you.
Christ infuses so much strength and power into you that you are strong for all things. You are not alone, struggling against mighty odds. Great power from Christ Himself has entered you and is there as a dynamo, an energy, a strength. Not I only, not Christ only, I and Christ, Christ and I, two of us.
Use the indirect approach! I must get to know and concentrate on knowing Christ. I must read the Bible, exercise, practice my faith in all its fullness. Abiding is active.
God controls the supply and the power. He infuses it.
Do not agonize in prayer beseeching God for power. Do what He has told you to do. Live the Christian life. Pray, and meditate on Him. Spend time with Him and ask Him to manifest Himself to you. And as long as you do that you can leave the rest to Him. He will give you strength…. He knows us better than we know ourselves, and according to our need so will be our supply. (“The Final Cure”, Spiritual Depression, L-J)