Ryan has diabetes but has no trouble functioning. One day, his wife informs him that she is leaving him. Ryan suddenly develops terrible pain in his back, to the point he is unable to get out of bed. His wife agrees to stay for "a while" to take care of him. Ryan probably has

Somatic Symptom Disorder.

Explanation:

According to the symptoms possessed by Ryan, it can be concluded he is dealing somatic symptom disorder; and this involves a person having a significant focus on physical symptoms, such as pain, weakness or shortness of breath, that results in major distress and/or problems functioning.

The individual here is said to have excessive thoughts, feelings and behaviors relating to the physical symptoms. The physical symptoms may or may not be associated with a diagnosed medical condition, but the person is experiencing symptoms and believes they are sick.