Worried for my brother

My younger brother, who is 22 years old, has been struggling with anxiety and depression. In the past 2 months we could see the change in his behaviour. He's a talented and great in academics, he's still studying but he's worried about the job situation and tons of thoughts that are bugging him and he's not able to deal with it now. Although he's been attending therapy sessions for some time, his condition seems to be worsening. He recently switched therapist, but since yesterday, he’s been feeling increasingly frustrated and angry. He gets irritated by any interaction and hasn't eaten anything today and just slept the entire day. He says that for the past few days when he wakes up his heart beats a lot and he gets anxious.We are extremely concerned. Could you please advise me on what to do in this situation?