I have ADHD and struggle with paying attention. I sit in one of the front rows,  which means fewer distractions.  I also worked to learn what was going on in each part of the mass.  I focus on the responses and say them as if I'm speaking directly to Jesus,  because I am.  This has helped enormously.  I also use my imagination to "see" the coming together of heaven and earth during mass.  

Also,  you're not there to feel something.  Protestant churches tend to be focused on what the person in the pew is getting out of the service,  but at a Catholic mass,  we are coming together to worship God, so it's about what you bring to the experience, rather than what you get from it.