It can be tough to respond to a calling from God when one keeps running into obstacles in pursuing that calling. It's especially important to stay close to God during this time and if possible stay connected to a spiritual director.
You are not alone in being over 50 and sensing a calling to a form of consecrated life. We regularly receive requests for information here at VISION and on aNunsLife.org and have looked for dioceses and religious communities that are open to folks over the age of 50. There are not many because of the expectation that a person be in good overall health and capable of participating fully in the mission and ministry of the lifestyle, whether ordained or religious life.
In general I have found that contemplative religious communities are more open to older candidates, and for men that may include the possibility of ordination. Vocation directors, however, are becoming more aware of the growing group of people over 50 who are called to some form of consecrated life. Although there is little precedent in our current forms, the church does have a form of life called the Order of Widows that could be renewed and revitalized for older women and men.
For you, now, I encourage you to go more deeply into God's calling to you with a spiritual director. Also, spend time with others who are sensing a similar calling—consider visiting the Vocation Forum at aNunsLife.org which has a new forum for folks over 50.Trust that God does in fact have something in mind for you, even if at this time you keep bumping into obstacles. I will be praying with you and will continue to keep an eye out for possibilities for you.