Among humans, the issue of being overpowered and losing control is not simple. This is because of your state, as you reside among humans on all levels of spiritual development and inclination. The extremes are present, from the sadist who looks for opportunities to torture others, mentally or physically, for the sense of power that this brings him - to the saint who would share a blanket in a snowstorm with another, equally. Has the saint been overpowered by the need of another? What of lovers, who desire the physical union such that they describe the merging in passion as drowning in love? Is this not being overpowered? What of the mother of a young child, who seeing the child in danger would without thought put herself in its place. Is not this mother overpowered by her desire to protect? Should someone decide to rush to help others, putting themselves in front of the flood, and thus being overpowered, feel themselves wronged?
This has no easy answer. In the 4th Density Service-to-Others, this has an easy answer. One can be overpowered by circumstances, but not by other entities. When one is overpowered by circumstances, it is as with weather or storm or accident. Service-to-Other entities do not desire to overpower each other. We desire to see each have the freedom to decide their own outcome, their own path. We support personal decisions, utterly. The personal decisions of the entities in the Service-to-Others orientation are not such that other entities are harmed. Only the entity itself is affected. Thus they have freedom.
However, in your human condition, where you are surrounded by other humans of all levels of spiritual development and orientation, it is possible to be overpowered not by circumstances, and not by a choice of your own, but by another's desire to dominate for their own personal sense of security or desire for power. This is another matter, much dramatized in the movies and in your literature. How to recognize when the line has been crossed? Is the infant's cry domination? You decide not. Is the child's dance in the center of the gathering domination? You view this with affection. Is the wife's demand for time away from family and work concerns domination? You consider this sexual and emotional need, and take it as a compliment, a form of desire.
When do human demands become domination, and when does human response to demand cease to be concern, but submission? A difficult call. To shield yourself from domination, it would be wrong to block all empathetic response. The child cries without respite, as the parent will not be dominated. You see our point. Likewise, the overgrown child who cries for attention, demanding a front place for attention when others are likewise hurting, can be treated as the child this person is, or can be brushed aside. Which is the path of greater spiritual growth? And is this domination?
In sum, this question cannot be answered for the human condition, where you are asked to sort out the various demands on yourself, according to the proper priorities. Each situation differs. The line between being empathetic to the insecurity and immaturity of others, and being dominated, is not easily deciphered. Those more spiritually adept can judge, and know when giving to others is toward a good purpose or toward serving an unquenchable self focus. Sometimes mistakes are made. This is how we learn. One may be used. One regrets. One may fail to respond to a demand in retrospect is reasonable, even poignant. One regrets. In the end, one grows, spiritually and in wisdom.