MacBook turns on but doesnt start up most of the time.

I've had this 13" mid 2009 Macbook Pro for more then 6 years now. More then a month ago I was browsing Youtube when my laptop screen went black suddenly. It was still powered on, because the fan was spinning and the keyboard light was still on. So I shut it down, and tried to turn it on again, and it got stuck in a black screen, and I didnt hear the usual chime that it does before going to the apple logo.

The next day I managed to get it to the white screen, but a flashing folder with a question mark popped up. I did some research, and managed to get to the Recovery Screen with CMD+R, did First aid to my hard drive, and it said that there were no problems. Restated laptop, and BAM it worked normally. After some hours though, when (coincidence or not) I was on Youtube again, screen went black and the same thing happened.

The problem is that right now, when I try to turn it on, it gets stuck on a black screen, with no chime, the fan is spinning, and the small sleep light stays on all the time.

This is what happens most of the time, which is around 60-70% of the times. When it DOES turn on, I can hear the usual chime, screen goes white and instead of the usual apple logo I get the flashing folder with a question mark on the middle.

CMD+R does not work anymore for some reason. Except the first time, it only worked one more time, I did First Aid to the hard drive again and it still said that there were no problems, so I tried restarting but it still showed the flashing folder.

I tried starting it with the Option key, and it actually starts up (not all the times though) till a white screen, but no startup drives show up, only the cursor. I should also mention that my battery life is almost at an end, not sure if that can create problems or not. I actually tried disconnecting the battery from the board and reconnecting it, but nothing changed.

I hope someone might have some knowledge of what it could be. Sorry for making it too long, but I wanted to explain it all as it happened and include as much details as possible.