Hi there ~
You feel sleepy when you start reading because it is something that you are not interested in. To get your interest levels up you might need to start doing other things to help with concentration. Yoga
, pranayama, dhyana, and regular physical activity are known to boost concentration. I would also recommend that you get evaluated by a psychiatrist
to treat your condition if it needs medication. I hope this helps.
Take care and have a nice day !