Physical and mental fatigue.

These symptoms have a number of causes including low thyroid, low adrenals, anemias, diabetes, liver issues, medications...........

Dizziness and spaced out feeling most of the time. Muscle and overall body stiffness.

Based on these symptoms I would lean more towards the adrenals.

Bloating, slow digestion.

The most common reason for this is a lack of stomach acid.

Body possibly producing too much Adrenaline

Definitely not. Too much epinephrine (adrenaline is an outdated term for epinephrine) would cause high blood pressure, a racing heartbeat and a nervous energy. Epinephrine also constricts the blood vessels creating circulatory issues and often a cold feeling.

or too much Cortisol (can't figure out which, body shaky at times).

Sounds more like a lack of cortisol due to adrenal dysfunction. A lack of cortisol output can lead to hypoglycemic reactions causing fatigue, shaking, mental fogginess and sweating.

Don't sweat much or like I used to.

Lack of sweating is a symptom of hypothyroidism. Hypothyroidism can result from adrenal dysfunction. Have you checked your basal body temperature to see where your thyroid is functioning at? Here are instructions:

http://curezone.com/forums/fm.asp?i=1446516#i

2 NDs said my adrenals are low. Racing thoughts that never stop, super active mind. No panic attacks but uncontrollable anxiety especially around people.

I recommend building up your adrenals with vitamin C and pantothenic acid sources and adaptogenic herbs. The adaptogens I recommend focusing on are ashwagandha, Chinese licorice root, astragalus,  suma and small doses of schisandra berry.  Nettle leaf, rosehips and watercress even though not classified as adaptogens are still great for helping to build up the adrenals.

Severe depression.

Again this could be from a long list of things including low adrenal or thyroid function.