i agree with alex..
its def a side effect of just about every psychotropic medication
u rote that ur susceptible for depression... are u currently in a depressive episode.. perhaps if ur not and if ur feelin alright maybe reduction of ur meds under ur docs guidence of course...
the best point from alex is about not seeing sex as goal orientated.. the more pressure u have on climaxing the harder it will be to achieve as the stress levels rise .. its better to be as relaxed as possible...
and for those who cant climax with partners but can with toys.. why not bring the toys in with the guy???