Maths is the subject that most often wrecks time management. A few long questions can eat the clock you needed for Physics and Chemistry. The fix is deliberate practice for both speed and accuracy.
Speed and accuracy are both trainable

Speed without accuracy wastes negative marks; accuracy without speed costs you questions you never reach. You need both, and timed practice is how you build them together.
Know where the marks live

Calculus leads Maths by a distance, followed by Coordinate Geometry and Algebra. Being fast in a low-weight chapter helps little; be fast where the marks are.
Practise timed, analyse hard

In Maths, an untimed solve teaches you the method. A timed solve teaches you the exam.
If Maths is eating your time, the culprit is usually a few specific weak chapters. Dakhilaa's diagnostic pinpoints them, so your practice targets the ones actually slowing you down.
Dakhilaa