Hello, I'd like to help you with your question.
It sounds like you may have something else going on besides the depression. It could be the PTSD as your doctor suggested, but besides the insomnia, the other symptoms you describe do not fit PTSD. Being overly sensitive to lights could be more of a physical issue. For this reason, it may be a good idea to see your family doctor to rule out any possible physical problems first before you consider a mental health issue. They should be able to perform an MRI or other scan to see if there is a cause for what you are experiencing.
If there is no physical cause found, you may want to explore the possibility of Bipolar
disorder. That might explain the depression and mood changes including the insomnia. In the meanwhile, you can learn more about Bipolar to see if you might fit some of the symptoms. Here is a resource to help:
You can also ask your doctor if there are medications that can help you sleep that you could take if you do experience the insomnia again. That way, you stop the progression of symptoms before you get to the point of not being able to cope. Here are some other ways you can reduce your stress
and help yourself manage your symptoms until you can get some further testing:
Relaxation- progressive relaxation of your muscles can help you learn to relax again. Lay down on your back. Start at your feet and tighten then let go of each muscle group. Do this slowly up your body until you reach your head. Do this each night and when you have time during the day. It teaches you how to relax and is useful when you find yourself feeling tense.
Deep breathing- people under stress often do not realize that they are breathing shallow which can cause you to feel lightheaded and tired. Practice taking deep breaths throughout the day to relax and center yourself.
Find time to relax- give yourself at least 30 minutes a day to do something mindless. Take a warm bath, listen to music, watch a favorite show, or take a walk for example.
Share your stress- talk to someone. Find support through family and friends. Do something with a faith group. Sharing your stress can help you feel less burdened and therefore less upset.
I hope this has helped you,