Firstly, you have various means to improve your physical health.
I think, if you join a gym ⛹ and follow your trainers Instructions, you might improve.
Secondly, your restlessness, could be for various reasons.
Probably, if you are unhappy about yourself or about something, Or,
You might comparing yourself with others due to environmental compulsion etc.,
Next Steps
To understand and accept yourself better, do consult a psychologist either online or offline by browsing in this forum itself.