50% ownership of condo

[abirch77]

My late husband and I owned our condo together as tenants in common, where we lived for 30 years. When he died, he left 50% of the condo to me, and the other 50% equally split among his 4 children, with the exception that I have the right to live in the condo for as long as I wish.
He died 2 years ago; I still live there. For 2 years, I've been paying full maintenance and condo fees plus all the property taxes, utilities, etc. Here are my questions:
1. Am I not entitled to 50% of the maintenance, condo fees, and property taxes - retroactive to when he died?
2. Can his 4 children force me to pay rent if I ask them to pay for their 50% share of the maintenance and taxes?
3. Can I sell the condo without permission from his 4 children, or can they sell without mine and force me out?
There was nothing written in his will or any agreement about terms of the 50/50 ownership other than the above.
Thank you very much,
Alanna Birch