I'm becoming increasingly paranoid. Does this mean anything?

This sounds like your anxiety is getting worse. I feel like that almost everyday and it can be scary. Talk to your parents and tell them. It will help because they could take you to the doc and they will subscribe you some medication that will help with it. I think your anxiety is getting worse, or if you have something to worry about, try not to think about it or ignore it. Nothing is out to get you, it's just your mind playing tricks. Hope this helps! :)

Possibly, but I am not 100% on it

Be sure to let the therapist you are seeing know how you are feeling. Your medications may need to be adjusted or you may need to be hospitalized so your condition can be stabilized.

I had all those symptoms and many more from vitamin B12 malabsorption. You need B12 for serotonin production. It does not mention B12 specifically below but you need B12 for methylation. I added two more links on how to boost your serotonin from exercising to getting enough sunlight to various supplements.

"Serotonin deficiency signs/symptoms:

Depressed
Nervous/anxious
Worrier
Fears/phobias
Negative/pessimistic
Irritable/impatient/edgy
Obsessive compulsive tendency
Think about the same things over & over again
Self destructive, masochistic or suicidal thoughts/plans
Low self esteem/confidence
Anger/rage/explosive behavior/assaultive
Sleep problems/light sleeper
Crave sugar/carbohydrates/alcohol/marijuana
Use these substances to improve mood & relax
Feel worse in and dislike dark weather
Chronic pain (e.g. headaches, backaches, fibromyalgia)
PMS
Antidepressants or 5-HTP improve mood
Family history of depression/anxiety/OCD/eating disorders

Serotonin levels may be low due to a combination of genetic and acquired reasons. Serotonin can be raised effectively using either nutrient based therapies or medications. Serotonin is synthesized from the amino acid tryptophan.

Factors which reduce serotonin levels:

Stress
PCB’s, pesticides and plastic chemicals exposure
Under-methylation
Inadequate sunlight exposure
Tryptophan (precursor) deficiency
Iron, calcium, magnesium, zinc, B3, B6, folate & vitamin C deficiency
Inadequate sleep
Glutathione deficiency
Chronic infections
Food allergies
Genetic serotonin receptor abnormalities
Chronic opioid, alcohol, amphetamine & marijuana use
Human growth hormone deficiency
Progesterone deficiency
Impaired blood flow to brain
Insulin resistance or deficiency"

Serotonin deficiency:
http://www.nutritional-healing.com.au/content/articles-content.php?heading=Serotonin%20deficiency

Balance Your Neurotransmitters to Take Control of Your Life:
http://bebrainfit.com/balance-neurotransmitters/

15 Serotonin Supplements to Boost Mood Naturally:
http://bebrainfit.com/serotonin-supplements/