Mathematics is not computation. If you like computing things, you’re better off being an engineer.
In any decent mathematics major, there will be a fair bit of abstract thinking. Most people find this difficult until they’ve had some practice at it. You’ll also be asked to think logically. Most people are pretty bad at this, too, until they’ve had some training.
Here’s a really really simple example:
You want the highest value possible of three numbers: a, b, and c
a < b; b < c
Which do you prefer: a or c?
Can you prove it?
Again, this is beyond simple, so if you have trouble with this, then you might want to consider that you’ll have a bit more work ahead of you. Then again, anything worth pursuing takes some work.