No, I do not agree that love is the only light we have in this troublesome world. Nor do I agree that Shakespeare indicates this in the play Romeo and Juliet.
In fact, if anything, I would argue that the play indicates a view that is very much opposed to this idea: love is powerful, but it is dangerous.
Look at the situation at the start of the play. Both Romeo and Juliet are leading relatively normal lives. There are things about their lives that frustrate them, or that they would change, but the world is hardly troublesome. Both are part of extended clans. Both have people who care for them.
Then they meet, and their love (or at least, passionate desire) changes everything. It seems to make the world much, much better.
But then, because of the situation and how they pursue that love, at the end Romeo and Juliet are both dead. This is due, at least in part, to love, and definitely to the fact that they loved without caution or social support.