Am I seriously ill?

Over the past year or two, I've encountered a lot of physical and mental problems, that could be symptoms to something that is quite bad. I'm at the point where I'm worried my life span might be shortening due to this.

Symptoms are:

1. Constant muscle tightness which causes constant stretching

2. Invisible rash that tends to occur when I have a drastic emotional change or when I change temperature quickly which makes my skin very itchy everywhere

3. Mood swings

4. Too much energy (I always go over the top and find it hard to relax)

5. Ruined sleeping pattern

6. Muscle spasms which cause me to stretch in very weird positions

7. Short temper

8. Loss of sexual interest

9. Aggression

10. Difficulty to keep focused on anything (e.g, lessons in school)

11. Easy boredom

12. Heart/lung pain (a sharp pain that does not go away until i completely expand my chest where a click is heard)

13. Avoiding responsibilities

I think personally it could be stress, but I don't know how to deal with it, and I don't know if i'm right. What should i do? Do i have a problem?