VOICE FEELS HUSKY
If it is due to muscle tension, then try the following:

Humming and gentle 'mmmm' - whilst doing this, try and keep your upper chest area as still as possible.

Have plenty of fluids.

Roll your neck gently - let your head drop to your chest and then move slowly towards one shoulder only as far as is comfortable, and then back the other way.

Lift your shoulders up towards your ears and then let them drop.

Swing and stretch your arms gently.


LARYNGEAL CONSTRICTION
Breathe in and out, with harsh air (like heavy breathing). Notice how it feels in your throat.
Do the same exercise but without any sound. Feel the throat widen as your vocal tract expands to let more air in and out so the tension is released.

The funniest exercise I found was, pretending to giggle or laugh. This actually works! 

SOME SIMPLE EXERCISES
These may feel silly to do but are very helpful. If possible, find a quiet corner where you can do them.