Unable to focus at all

Hey all , I am trying to study a course for upskilling myself to switch for a job but i am unable to focus at all. I am too much distracted and feel so low on dopamine. I am either continuously shaking my legs or chewing the pen, picking the phone again and again or thinking to masturbate or eat something sugary to fix my dopamine needs. On meds, I was highly able to focus but I had to stop them due to severe side effects of high blood pressure and heart rate. I have been exercising, taking caffeine and using reminders to complete my daily chores but i am unable to focus on my studies at all. I am feeling so miserable as i am stuck on same salary since last 3 years and I need to change my job. What do i do? Please help me.