Even in times when we are all alone, we do feel him, if, we open our hearts to him first that is. The most profound experiences of God are had in the most desperate situations. In our deepest suffering, turmoil is when perception of the Divine truly takes place.
God however is with us at all times. His love shown in all things.
Love of humans is in itself an expression of God's love. We each have a set of people who dearly love us. However, often we become unhappy with loved ones because we start expecting God's unconditional love from them. Well, sadly, humans are not God. We strive to follow his good example but we repeatedly fail.
So as important as it is for us to learn to love the other person unconditionally, equally so is to learn to not expect unconditional love from the other person. Know that God alone can give us that love which will satisfy us. Know also that love of humans is also a fragment of God's love.