Hello,
No it's not normal. At your age it can be Anxiety. Anxiety symptoms are usually free floating i.e., it comes and go anytime. Symptoms include worries about future misfortunes, feeling "on edge", difficulty in concentrating, restless, headaches, feeling dizzy, inability to relax, sweating, increased heart beat, gastric discomfort, dry mouth etc. Few or all of these can be present. It can be taken care off with the help of medications and psychotherapy. The other possibility needs to be rule out so consult doctor as early as possible.
Next Steps
Consult nearby psychiatric clinic.