Adyashanti talks on being alone. I wrote about this before in another post Being Alone Does Not Need To Be Lonely that also may interest you.
Often being alone is also indicative of not being connected to yourself. 
Below is a guided audio that may assist you in finding yourself again and within that connectedness you find wholeness and will no longer feel alone.

At some point in our lives, we come to a maturing when we are authentically ready to go deeper into relationship with another being. We are truly “feeling into” the possible for “love”. Some of us become confused within this journey as our authentic journey for experiencing love is intimately intertwined with our behaviours, the human persona or ego as some call it. If we are still caught up in our behaviours of “closing down” due to wanting to “protect” ourselves from pain, before we trust love, then we will not able to “attract” a partner at the level we really wish to choose as we are not yet really living as LOVE.