If you are depressed, you need to take depression medication. Wellbutrin is a depression medication.
If you have insomnia, you may have primary insomnia, which Ambien will help. However, a lot of patients who have insomnia have depression, so treating depression will also help treat insomnia. However, insomnia can make depression worse, so a lot of time, people will need both depression medication and sleeping medication.
Trust your psych nurse. If you have problem, you need to ask your psychiatrist.
Also, don't expect to get off medication soon. Studies show that taking depression medication for more than 12-18 months will decrease the chance of recurrence from 1 out of 2 to 1 out of 5 in 1 year; also studies further shows that once you have depression, there is a 50 percent chance of it recurring, but if you have depression twice, there is 75 percent chance of recurring, and three or more times, 90 percent. So, stay on your medication unless your doctor takes you off.