For what it's worth, I think to know whether a life is your calling or not you best had simply be practical about it. How would I do in these conditions? Would I improve spiritually? Or would I not? Can I live this life and bear its hardships and benefits?
You know your virtues and weaknesses enough to discern to some degree. Of course nothing is wrong with simply trying it and testing it out.
It may be a hard life, you may struggle a lot, but it's what you need. It's a life where you grow in virtue and where your flaws are compensated sufficiently for so as not to cripple you.
There're some books on Vocations on Saints' Books. And I think the Desert Fathers are always especially good reading for living a solitary life.
People come into their callings in life in different ways with different feelings..
I know someone can become too solitary too soon, because you do need spiritual guidance and help in some amount.