Guidance regarding Masturbation issue.

Background- 1. I am 22 yrs old. 2. On Neurological medicines since early childhood. 3. Started masturbating at age of around 17. Very rare masturbation earlier. Doing once a week more recently. Had nightfall issues earlier. Not experiencing now. 4. Gymming irregularly for last 3-4 years. Changed Gym supplement protein + egg + non-vegetarian diet since 20 days. Issue- 1. Last sunday, masturbated, penis erected properly, ejaculation semen very less, almost non-existent. 2. Masturbated this sunday(yesterday), ejaculated, but erection not proper, very flexible penis ejaculation. Erected(not to full extent) for few seconds that too post ejaculation. Guidance I am this young 22 year lad's elder brother typing on behalf of him. He is literally crying over phone to me. He is mentally too stressed thinking he may be having infertility issues in future. He has even dropped the new diet plan. How to guide him? Does he need medical attention or just a regular thing? Kindly guide.