I did not read the other posts, but let me reasure you, unless your daughter has been alone in a room with a TV for two years, she was with people everyday, then her attachment to TV is a symptom and not the cause of her issue. 8 to 10 hours of TV a day may not be ideal, but the TV did not feed her, the TV did not change her diaper, and I assume that you have had some contact with her over the last two years, so she has had human contact.
I have a child with a developmental disablity, and she took to TV at about 18 months, and from the moment she saw it, she was in love. Your child is doing exactly the same thing she did, and in my work as an educational advocate, I have found that many kids with developmental issues take to TV this way. TV does not cause children to avoid eye contact. TV does not cause repetetive speech (echolalia) and children who won't speak otherwise do not know how to spell the cartoon's names and act out what they do, I have seen that behavior, and it was not just because of TV. TV is something some kids with developmental disabilities can hyper focus on. You are seeing an effect, not a cause.
If you want to take no chances, make some phone calls in the morning. First, call the nearest children's hospital and ask for the Developmental Pediatric department and make an appointment with a developmental pediatrician. This will take several months before you get in, but keep the appointment and fill out all the paperwork they send you. Get someone to help you fill it out if you need it, this is very important.
Call a speech therapist near you and make an appointment for a speech evaluation and start speech therapy. She may say words, but she needs therapy because she is not using langauge to communicate.
If money or insurance is an issue, call Easter Seals. They may be able to help you. Also call the county, they will have early intervention services, although it will probably take a long time to get these, and you will be nearing three before you do, and after age three, contact the school district for evaluation, but never depend on state services to be everything she needs. It won't be enough. You should begin the process with the county board of MRDD, they will be able to help you with the services in your area too.
I am not going to say what my daughter's diagnosis was, because that may not be helpful to you, but I can say that from where I sit It is not too late, but let go of the idea that TV caused this issue. Your daughter has a clasic presentation, and if you continue to focus on the TV, you will not access the services she needs. You need help, start tomorrow.
M.