How to overcome constant fatigue and sleepiness throughout the day in a female on antidepressants?

Hello doctor,

I have constant fatigue (i.e. nodding off 10-20 times a day). I constantly feel like sleeping all the time even when I wake up in the morning till lunch, then after lunch, I crash badly some days. I am exhausted every minute of the day. I always live in pain from a car accident that happened in the past, but this is the first time in my life I have felt this groggy and tired. Some days I have much more energy then after a few days I am a mess. I get distracted easily, am foggy-headed, cannot concentrate, stare into space, and get a bit OCD about things like cleaning or making sure my environment is clear so I can work and focus, but I struggle even with that. When I need to sleep I need to stop my work immediately. Yesterday I had to sleep very quickly, I felt like I was drunk and I kept mumbling which was very strange. My diet is mainly good clean protein, good fats, greens as I am lactose, fructose, and gluten intolerant, and lots of water. I work from home as a graphic designer. Last year, I was competing in a fitness competition. I am quite healthy otherwise.

I have mentioned below my details:

1. Sex: Female.
2. Age: 44
3. Weight: About 62 kg.
4. Height: 162 cm.
5. Current medication: Zoloft 100 mg.

I do not drink, smoke, or use any drugs. I am taking vitamins (high-grade iron, multivitamins) mostly in pre-workout so that I can stay awake and function. Recently I took certain tests and everything is okay. My thyroid, white cell count, and insulin levels are normal but my iron was 8 (should be over 15 from what I was told) which is a little low but the doctor said I am on my reserves and that I would be fine. I have never been able to make my iron levels high. My blood pressure was spot on, and even my sexual health tests were fine. I am a single mom of two kids with 90 % care. They are 12 and seven years old. My son has been diagnosed as autistic. I do have extreme stresses (mostly financial at this time), depression, anxiety, PTSD, OCD, and Agra/agoraphobia (following sexual assaults). I am concerned I might be bipolar even though the psychiatrist said I am not. I know depression can cause some of these symptoms, but I wanted to ask what I should do next. Any second opinions? What can I do? To whom should I speak? What can I do to help myself? How can I stop falling asleep as soon as I sit down?