Life is a test , never despair
Allah states that He made this life in order to test man so that every person may be recompensed after death for what he has earned:
[He] who created death and life to test you [as to] which of you is best in deed - and He is the Exalted in Might, the Forgiving. [Quran, 67:2]
Satan will cause you grief & stress. When you keep having negative thoughts of pain & sorrow, he will worsen your condition. So get a perspective on life. Remember, this world is a mix of ease & hardship, joy & sorrow, hope & pain. Do your best to adopt a positive mindest!
A powerful supplication to say for protection of all sorts of illness:
Anas reported: The Prophet, peace and blessings be upon him, would say, “O Allah, I seek refuge in you from leprosy, madness, degenerative diseases, and evil sicknesses.”
Source: Sunan Abī Dāwūd 1554
Grade: Sahih (authentic) according to Al-Albani
عَنْ أَنَسٍ أَنَّ النَّبِيَّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ كَانَ يَقُولُ اللَّهُمَّ إِنِّي أَعُوذُ بِكَ مِنْ الْبَرَصِ وَالْجُنُونِ وَالْجُذَامِ وَمِنْ سَيِّئْ الْأَسْقَامِ
1554 سنن أبي داود كتاب الصلاة باب تفريع أبواب الوتر باب في الاستعاذة
1554 المحدث الألباني خلاصة حكم المحدث صحيح في صحيح أبي داود