What were your peak activities during that time ? It is not the amount of rest that is important but rather reducing peak activity levels. But then, you just may need more time. Some do.

Are there any other stressors in your life ? Family or relationship issues, financial, household, job struggles, etc. All can contribute to anxiety and depression. The head pressure can take a long time. For me, it has not been uncommon for head pressure to last 6 months to a year, then return from time to time for no understandable reason. The strain of feeling uncomfortable can feed the depression/anxiety issues.

Zoloft can also have negative effects.