Another way that people try to deal with their loneliness and anger is by refusing to be alone. Such people can get so bad that they will put up with anything rather than take a look at themselves in the mirror. This is slightly different than off loading on people. It is inward rather than outward looking.
To borrow a phrase from a Leonard Cohen song, it's like living off the crumbs. This is evident in an abusive relationship when poeple seem to put up with terrible 'put downs' in public etc. There is also a cycle that develops here. Yes, there is a desire for emotional comfort from the victims perspective, but the 'put downs' reduce self-esteem until the person does not feel they have the strength to leave the bully.
The existence of 'feeders'- viz, people who constantly feed their partners until they become massive- relates to this. Such 'feeding' is interpreted as an act of love. But this is also motivated by the fear that a partner may leave. If the partner is so unattractive that no one else would want them, then the feeder can feel more secure in that relationship!
Human beings are certainly complex and feelings can manifest themselves in a manifold manner. The key is to try and discern the underlying motivation. It should be mentioned that such an attempt to discern motivation should be treated with caution. It is always easy to misjudge such motivations, especially in relation to people we are close with.