Why are my OCD thoughts repetitive?

Information given by you ( some mental or brain related issues)is insufficient to arrive to proper diagnosis, Repeatedly shaking of head needs to see a neurologist, rather than endocrinologist, talk with your therapist for further treatment

This is more common than you may realize and could be due to stress affecting your body. When you’re nervous, it can make your body react in various ways such as increased heart rate and release of semen. Perhaps trying relaxation methods like deep breathing or talking about what’s bothering you with someone could help calm down your nerves before sitting for an exam. 

Hallucinations can be a sign of many underlying conditions I suggest that you go to psychologist as soon as possible in order to find out the cause of your hallucinations. You need to give thorough medical history to the doctor in order to help with the diagnosis. Do not medicate yourself. Instead, seek professional help.
 

The symptoms you're describing could be due to a panic attack, which can sometimes mimic a heart attack. It's important to address this issue promptly. Make sure you take your antidepressants consistently as prescribed and consult a mental health expert for the best way to manage your anxiety. Stress management techniques, like deep breathing exercises, can also help with these symptoms. 

BIPOLAR DISORDER IS A MOOD DISORDER MARKED BY EXTREME CHANGES IN MOOD, ENERGY, AND ACTIVITY LEVELS . Symptoms include manic episodes with elevated mood, hyperactivity, and impulsivity, and depressive episodes with low mood , decreased energy, and feelings of worthlessness.. Diagnosis is made through a comprehensive psychiatric evaluation, including a medical and family history , a physical exam, and lab tests. Treatment involves mood stabilizers, antipsychotics, psychotherapy, and behavioral interventions. Early detection and treatment can help manage symptoms and improve quality of life. Please seek an expert help without delaying

If you are enduring the pain of a headache and overthinking while studying, it is vital to attend to the root issue. I advise you to refer to a neurologist to exclude possible medical problems of headache origin. As well, you can try to get support from the mental health professionals, like psychiatrists, who can show you how to manage your tendency to overthink and develop the necessary discipline and consistency in studies.

When you get anxious, your body can start breathing too quickly, a condition known as hyperventilation. These symptoms can make you feel out of control, and shaky, and your heart might race fast. It occurs as a result of the brain's misinterpretation of the need for more air when the actual need is not. A technique called paper bag breathing, as well as breathing slowly, can help. Among such are uplifting leisure exercises such as mindfulness and deep breathing to mitigate your anxiety.

Anxiety, dizziness, palpitations, and depression can be tough to deal with. You often feel anxious, which makes you worry a lot. Dizziness may feel like you're about to collapse, and palpitations are when your heart beats faster than usual. Depression causes you to feel sad frequently. These feelings can be caused by stress, lack of sleep, or health issues. To get support, try to calm your mind, maintain a regular sleep schedule, share your feelings with someone you trust, and consider therapy or counseling. These steps can help you manage your emotions better.

No, it won't but it is important to consult with a psychiatrist for the proper diagnosis and treatment of depression as well as any related conditions.

You’ve had a tough time dealing with erectile dysfunction before, and sometimes, medical conditions can be a cause. Feeling down or stressed can also affect your ability to get an erection. The good news is that your current medication seems to be helping. As your mental health improves, your ED might get better as well. 

If you take propranolol before skydiving, that might not be safe. Before such a high-energy activity the drug may slow down your pulse and lower blood pressure, which is risky. During acute stress situations such as this one it is necessary for the heart to beat fast so as to supply enough oxygen into the muscles thus enabling them carry out their functions effectively.