Donovan is incapable of loving and, therefore, has never loved you (or, for that matter, anyone else, himself included) in his entire life. His natural capacity to love and to return love was all but eliminated by his horrid childhood. We practice loving first and foremost through our parents. If they fail us, if they turn out to be unpredictable, capricious, violent, unjust – this capacity is quenched forever. This is what happened to Donovan: the ideal figures of his childhood proved to be much less than ideal. Abuse is a very poor ground to breed healthy emotions in.
Granted, Donovan – being the brilliant and manipulative chap that he is – knows how to perfectly simulate and emulate LOVE. He acts lovingly – but this is a mere act, nothing more substantial and it should not be confused with the real thing. Donovan shows love in order to achieve goals: money, a warm house, food on the table, adoration (Narcissistic Supply). Once these are available from other sources – the former ones are abandoned callously, cold-heartedly, cruelly and abruptly.
You have been such a temporary stopover for Donovan, the equivalent of a full board hotel (no chores, no requirements on his time). Not only was he able to secure his material needs from you – he also found in you a perfect Source of Narcissistic Supply: adoring, submissive, non-critical, wide-eyed, approving, admiring, the perfect narcissistic fix.
You describe a very disturbed young man with a clear NPD. He values intelligence above all, he uses “horrendous” language to vent his aggression (the narcissist resents his dependence on his sources of supply). The narcissist knows it all and best, is judgmental (without merit), hates all people (though he will call upon them if he needs something – he is never above exploiting and manipulation). When not in need, he does not contact his “friends”, not even his “girlfriend”. After all, emotions (“sensitivity”) are a dangerous weakness.
In the pursuit of narcissistic gratification, there is no place for hesitation or pause. You put it succinctly: he will do nothing for others, nothing is important to him if it is not for himself. As a result, he lets people down and refrains almost religiously from keeping promises and obligations.
The narcissist is above such mundane things as obligations undertaken, they counter his conviction that he is above any law – social or other, and this threatens his grandiosity.
The narcissist, being above reproach (who is qualified enough to judge him, to teach him, to advise him?), inevitably reverts to blaming others for his misdeeds: they should have warned/reminded/alerted him. For instance: they should have woke him up if they desired his precious company.
The narcissist is above normal humans and their daily chores: he doesn’t think that he needs to attend classes (that others do. This is the unspoken continuation of this sentence). Other people should do so because they are inferior (stupid). This is the natural order of things – read Nietzsche. Most narcissists are predictable and, therefore, boring.
To love a narcissist is to love an idealisation, not a real figure. Donovan is the most basic, primitive type: the Somatic (or anal) Narcissist, whose disorder is centred around his body, his skin, his hair, his dress, his food, his health. Some of these preoccupations have attained a phobic aura (“freaky with germs”) and that is a bad sign.
Hypochondriasis could be the next mental step. But Donovan is in great danger. He should seek help immediately. His NPD – as is usually the case – has been and is still being compounded by other, more serious disorders. He is led down a path of no return. Donovan is constantly depressed. Maybe he has few major depressive episodes but he is distinctly dysphoric (sad) and anhedonic (hates the world and finds pleasure in nothing). He alternates between hypersomnia (sleeping too much) and insomnia (not sleeping for two days). This is one of the surest signs of depression.
Narcissists suffer, by their nature, from and undulating sense of self-worth and from all-pervasive feelings of guilt and recrimination. They punish themselves: they dress in ragged clothes contrary to their primary predilections and they direct their pent up aggression at themselves. The result is popularly known as depression.
Donovan also seems to suffer from a schizoid personality. These people prefer to stay and work in their rooms, in solitary confinement, chained to their computers and books – over any social encounter or diversion. They rarely possess sufficient trust in others and the requisite emotional baggage to develop stable interpersonal relationships. They are miserable failures at communicating and confine their interactions to first degree relatives.
The total picture is that of a young person suffering from a Borderline Personality Disorder with strong narcissistic and schizoid hues. His reckless and self-destructive spending and his eating irregularities point in this direction. So does the inappropriate affect (for instance, smiling while pretending to shoot people). Donovan is a menace above all to himself.
Borderline patients entertain suicide thoughts (they have suicidal ideation) and tend finally to act upon them. This aggression can perhaps be directed elsewhere and result in catastrophic consequences. But, at best, Donovan will continue to make people around him miserable.
Treatment – psychoanalysis and other psychodynamic therapies included – is not very effective. My advice to you is to immediately stop engaging in “unconditional love”. Narcissists sense blood where others see only love and altruism. If – for masochistic reasons, which are beyond me – you still wish to engage this young person, my chief advice to you would be to condition your love. Sign a contract with him: you want my adoration, admiration, approval, warmth, you want my home and money available to you as an insurance policy? If you do – these are my conditions. And if he says that he doesn’t want to have anything to do with you anymore – count your blessings and let go. Omar al-Khayyam, the famous Persian poet once wrote: when you want to have the bird – set it free.