ZMA Center Controller reported the radar often does not work and that multiple frequencies need to be fixed and better maintained.

Narrative

This is now my nth report of frequency issues in my facility. My frequency went out completely and I could not hear any readbacks coming from aircraft during the busiest day our building had ever had. I was also not sure if they were hearing anything I was saying. Without hearing read backs I was unable to verify instruction was received by pilots. I was unsure they would do what I needed them to do to prevent conflicts and collisions with other aircraft in my sector. There was no backup frequency.I was once on an aircraft that almost couldn't take off because they were missing a flashlight. My facility has broken frequencies and broken radars which go down on a routine basis. So much that it has caused several people to leave the profession all together. This is an unsafe environment for both employees and for aircraft flying though our airspace. There are several chunks of airspace that currently have no backup. If one frequency goes down there is no alternative. This just happened to me during the busiest day of the year.The frequency is my engine and the radar is my wings. It seems the FAA is not following its own safety standards that it sets for the users. It would not allow a plane to fly with broken equipment. Why does it allow itself to make do with broken equipment and no backup?I have never felt the feeling of complete hopelessness. I have never felt so defeated. The job tests your fight or flight response. We must fight. That is the requirement of the job. This is the first time in my multi-year career that I felt like walking away from an active sector.Recommendation: MYAF; MYBS; MYEF; MYGF frequency sites need to be fixed and maintained to a higher standard. GTK radar needs to be fixed. NOW!!!