Practicing, as I've said before, isn't just about playing through the tunes. You need to have a goal and purpose in mind when you practice. For instance: The first goal that I think you should have with any tune is to know the rhythm. Take out your pencil and write in the rhythm syllables. Then see if you can say them in a string. When you can do that, then you tap your feet left, right, left, right and say those syllables to the beat. Here we're talking about only three steps to develop the rhythm. Each one has to be completed before you go to the next.
Let's talk about the tunes. I think that your first goal should be to be able to play each and every note "big, slow and open" period. When you can do that and play while tapping your feet to the eighth note, then your goal is to be able to play at "parade speed." Remember, att some point you DO need to play at parade speed. Let's say that you start out at parade speed but find that you flub on the Grip on C. Just like "Stop, Drop and Roll" you need to "stop, isolate the problem and drill". You want to do that with every problem that you encounter.
By practicing in this manner, you can make more of the limited time you have for practicing.
Gary Guth is a professional bagpiper with over 45 years of playing experience and has been teaching bagpipes full time for the last 20 years. He has written "Bagpipes For Beginners", "the Bagpipe Hymnal", and " A Piper's Christmas".