Should I ask my landlord to lower my rent due to Corona?

It's always worth a try to speak with your landlord, but in most cases, you won't be successful unless you can explain/prove a financial hardship such as loss of income. It also really depends on your landlord's personal empathy and their own financial obligations. If your landlord has maintenance workers, utilities, etc to pay then they might not able to bend the rules as much.

If you want to break your lease, read over your lease. You might not only lose your deposit but also be obligated to pay the rest of the rent that you own according to your lease. You might have an easier time breaking your lease if there is something your landlord has not fulfilled, such as your apartment is not habitable due to damage, mold, heating issues, no running water, etc.