I am no diagnostician, but I used to teach a preschool class for children with developmental delays and autism related disorders. A lot of the symptoms you are describing in your son set off warning bells for me. The language delay, the toe walking, the pulling you to things he wants are all symptoms of developmental delays and/or an autism spectrum disorder.
Please talk to your pediatrician. He/she should give you information about contacting Babies Can't Wait. If he/she doesn't, please contact them yourself. Here is the website:
http://health.state.ga.us/programs/bcw/
This is a program funded by the state that provides services (such as occupational therapy, physical therapy, and speech therapy) at no cost to the family for children with developmental delays. There are no income level requirements, this is available to all families with children who, based on their evaluation, need services.
When you contact Babies Can't Wait, they will set up an evaluation of you child, and based on what they find, will come up with a program to address his issues. All services are provided by licensed therapists and are usually given in the child's home environment (or daycare if that is the case).
Best of luck to you! The earlier you address his issues the more success you will have in overcoming them.