Macbook Pro Not Booting

I have a 2010 MackBook pro which I have had restored and upgraded about 2 years ago.

Now it does not want to boot up, the screen remains black and the light indicating power on does not stay on.

When I hold in the power button the screen does come on it asks me why I cannot log in?

If I go to the About Startup Disk menu it says my drive is encrypted and locked. I have clicked unlock but it just restarted the whole process again - doesn't seem to be working.

Is there a way for me to fix this or has the SSD gone and need to be replaced?