I hear you about math class and losing motivation because you just don't know how to do it right.
I like Focused and Fearless by Shaila Catherine -- very clear with lots of exercises to help you get it right.
The Mind Illuminated by Culadasa is a very step-by-step meditation guide.
Or try Thanissaro Bhikkhu's guided meditation recording at dhammatalks.
Pick something and stick with it.
Just my 4 cents.
(w/o your personal jumping coach, you'll still have to do some of your own diagnosing and trial and error.)
Pretty sure staring at the ceiling and drifting is not it.
Edit -- Unless your "drifting" is actually this:
Stay mindful, monks, and alert. This is our
instruction to you all. And how is a monk mindful? There is the case where
a monk remains focused on the body in & of itself—ardent, alert, & mindful
—putting aside greed & distress with reference to the world. He remains
focused on feelings... mind... mental qualities in & of themselves—ardent,
alert, & mindful—putting aside greed & distress with reference to the world.
This is how a monk is mindful.
And how is a monk alert? There is the case where feelings are known to the
monk as they arise, known as they persist, known as they subside. Thoughts
are known to him as they arise, known as they persist, known as they
subside. Discernment [vl: perception] is known to him as it arises, known
as it persists, known as it subsides. This is how a monk is alert. So stay
mindful, monks, and alert. This is our instruction to you all.
SN 47:35
This is pasted from Thanissaro's
Wings.
Those who grasp at perceptions & views wander the internet creating friction. [based on Sn4:9,v.847]