Can my boss send me home and tell me not to come back until I am fit to work?

I have had a few problems in the last 3 months, a low level cancer lump removed from my back in November, having a hearing aid fitted in January, losing large quantities of hair to alopechia and losing my sister suddenly to bronchial pneumonia just after christmas and my brother in law to heart failure the same week. I took one day off after hearing about my sisters death and subsequently took 2 days off for the funerals, my sister in Bournemouth and the following day in Harwich. I had to use my Annual Holiday for funerals on the 27th and 28th January. I believe that I have been very careful not to take my problems to work and have tried to maintain reasonably normal whilst there. However on Thursday last week I was called into a meeting by my MD and Sales Director and told that I was spreading negativity, acting uninterested, looking through people, not listening and generally causing the business to suffer. I firmly believe that I was being treated unfairly and said so. They said many other things and also that they did understand that I had been through a lot recently but I had to pull myself together. I was extremely upset by their aggression and said they had no concept of what I had been through. I was told not to pull that one on them and to go home until I was fit to work. I left the building absolutely distressed and ended up going to my doctor in that state. He has given me a sick certificate for a week which I will send in. My point is that, I do not think I have been doing a bad job and I also do not think their summary of my behaviour was correct. I was so upset by their treatment that I did look like I was not coping when I went to the doctor but it was because of their treatment not my issues ( I have an excellent network of family and friends and am working through any issues I might have had really well) Now, I am so upset, I really don't want to go back at all. I have been there for 9 years and considered these people to be friends. I don't know what my rights are. I honestly can't think of anything worse than trying to work with 2 people who turned on me so nastily. My question really is, what on earth do I do now? If I send in the sick note, it looks like they are right, because I am now signed off for Emotional Distress Bereavement Reaction, but it was really Emotional Distress caused by the meeting... help