My ADD Medication seems to 'No longer work'

Hello everybody.

So I'm a 20 year old college student entering my 4th and (hopefully) final year of university. I have Tourette Syndrome as well as ADD. When I was in high school I never had to change my medication once--it worked so well for me and I never had any problems with it. My ADD was very mild and I was almost always on top of my game.

Around the same time that I entered college I began to notice that I was finding it much more difficult to focus on things that my friends, professors, and family members were saying to me. I started off thinking that I was actually going deaf--I listen to death metal frequently and I listen to it LOUD (probably not the best idea to say this on a health forum, but who cares ), so I thought that I was unable to hear large parts of sentences that were being spoken to me because I was going hard of hearing. Roughly 3 years later I can definitely say that is not the case.

Every year it seems to get worse and worse, and I find myself having an increasingly difficult time focusing, staying organized, and remaining fixated on important events that I am a part of. For instance, I often find myself 'drifting' during my classes for large periods at a time--often, in an hour and a half long class, I'll 'drift' for about HALF of the class--missing a ton of information on my notes. I hope you all know what I mean by drift--I'm basically in 'la la land'. My teacher will be up there talking about Oedipus Rex and I'll be sitting in my chair looking on intently but instead thinking about how Mariano Rivera just tore his ACL and then subsequently becoming engulfed in a large train of thought about baseball and so on and so forth.

I play hockey and I've played hockey almost all of my life. I never had problems staying focused on the ice but I'll be out in the net (I play goal) and I'll lose focus completely and will be late to react on a play coming towards me because I'll be so lost in my own little bubble of thoughts that I don't even see or hear the play coming towards me.

I guess what I'm trying to say with this ridiculously long post is that the ADD medication that I've taken for so many years seems to no longer 'work'. I don't even know if that's actually possible, but it certainly seems that way. My ADD is becoming more and more out of control and it's been affecting my life more and more. I scheduled an appointment with my Neurologist, but the earliest he can see me is late July...until then, I'm at a complete and total loss over what to do.

What can I do to prevent these all-too-frequent losses of focus until I can see my doctor and fix my medication?