Well, considering that you're both seeing a therapist or counselor--it shows that both of you care, which probably may give the impression that both of you have quirks and errors, but both of you care as the crux. As Arx said, trust your counselor/therapist as they're certified and registered professionals in order to give advice such as that to you (their profession: Help for your well-being. Their experience? 4+ years of studying things like these and many more, depending on their credentials and such).
Either way, the focus still also remains in part with you and how you collect and control your thoughts and words--and how you interpret others' words. The idea of trust, in that case, has to take into perspective many more things rather than previous basis, given that you're both seeing a therapist about it (which already implies that he//both of you are willing towards becoming better, together). Self-reflection on deeds done, and re-reflection on deeds to do, both on your part and on others/his also help open analysis of the situation. :O Sometimes, previous bad experiences influence how we see things, which lead us to assume certain ideas which may...really not be that healthy for us or for others, especially when some incidences really make us believe the unhealthy conclusion and react in ways which stress both ourselves (ie higher blood pressure...raised voice...tensed muscles...blurry thoughts, etc...) and them (all pertaining @the blowing up part), so its always best to keep an open-mind, a patient rhythm, and an accepting clarity [ie accepting personal faults; nothing wrong with that. That's a strength! When coupled with the will to get better, and the will to get mutually better]
Though yes, what Arx said. Trust your counselor/therapist--its a job people spend many years for, and a lot of work to achieve the credibility they have.
To rerail this thread: My sad is that sometimes--the negative effects of the media add to the negative reputation of the mental health field -_- ie Stigma and discrimination due to only <1% of instances which occur which capture the eye of the media (ie {bad} or unethical procedures done by acclaimed mental health professionals). The sad part is it lasts and generalizes institutions which actually forward the advance of understanding and aid of mental health, all because of those vocal few.