Over The Past30 + Years Ive Delt With Concentration Issues

Over the past30 + years ive delt with concentration issues poor grades to being talked to at work about my lack of productivity and although it was never stated, i feel like ive been let go from other jobs in the past due to similar issues. Been at a new job fir last few months and been having problems still. Is there any thing i can do to correct it or help with the concentation and lack of motivation. Thsnk you for your time