What is wrong with Melissa?

I haven't added to this blog for a long time as i have had alot going on in my life. My grandad died, my eldest sister became a widow at the age of just 27, my nan has been in and out of hospital like a yoyo, my uncle had a heart attack. The list is endless. Whilst all this was going on, my daughters behaviour was gradually becoming worse. (I originally thought it was just the terrible 2s). She screams and kicks and thumps her bedroom door when we put her to bed at night. She tenses her entire body and screams when we try to put her in her buggy to go out. She has become violent and quite often when i call her name, its almost as if she is deaf. She doesn't hear a word i say. (Her hearing is actually perfect). We have spoken about it to Melissa's speech and language therapist and to the GP, both of whome are completely useless and must think im a paranoid idiot as all they keep saying is ''She is fine, there is nothing wrong with her''. My answer is always the same. ''How could you possibly make that judgement when you do not live with her?'' It is almost as if they feel that because i am only in my 20s, i do not know anything. This attitude really annoys me. Melissa's speech and language therapist has sinse admitted that she has seen signs of autism in Melissa. We are now being referred to a child support worker from the childrens centre who will come out to our home each week to help us deal with Melissa's behaviour. They do not want to refer her to be tested for autism untill she is atleast 3 because the chances are, she will not get a diagnosis this early which will make it harder to get a diagnosis later on if it is discovered that there is a problem with her. I would love for there to be nothing wrong with Melissa, but i cannot ignore my gut feelings.