I second everything FairyCrystal said.

On a more "theorical" point, if you wanna be more open-hearted, picture yourself on a highway. During meditation/prayer is better.

Don't worry, it's closed today, no cars to hit you. Can even hear seagulls not far.

Are you ready ? Let feelings come to you. Stop worrying about anything. They'll find a way, they have a highway just for themselves after all.

Opening the heart chakra, is opening yourself to the unknown, any given second, not only that, but on top of it being welcoming for the unknown !

Be well