Inability to sleep properly. eating makes me feel a bit nauseous. head and muscles feel weak and heavy. could this be symptoms of exhaustion?

There are many...: Possible causes (pregnancy, medical problems, anxiety, depression, stress) for the symptoms you present. Work on sleep hygiene/get better rest; maintain proper regular nutrition with foods that produce the least nausea. Address any issues that may be causing anxiety or depression. Reduce stress in your life. If sleep & eating improve but symptoms persist or worsen, seek medical evaluation.