Not a dumb thread at all.

Yes you see the sleep deprivation/insomnia can cause your memory/concentration issues.

The other thing to note is that one of the symptoms of depression is early waking and anxiety can make you feel so anxious that you may have trouble getting to sleep. So, it's like a chicken/egg thing. The correct amount of sleep will help you but you will need to get treatment for the depression and anxiety.

You don't need to see a sleep doctor, just a regular doctor will do to get some medication for your mental health and sleep.

To aid a restful sleep -

Do not eat too late.

Make your bedroom comfortable.

Have a bath to relax you.

Come off the internet and stop studying at least one hour before going to bed.

Practice relaxation techniques, you can buy a CD to guide you through the process of relaxing your whole body.

Go to bed at a reasonable time and get up the same time each morning.

Visualize a safe place.

I hope this helps.