Hi Anna, hope you're feeling a little better. I have more time to write now.
First, do you have help from Early Support / Portage? Our portage worker was a great help and good for signposting us to other organisations. She put us in touch with the Papworth Trust who are a charity who help with DLA applications. They may not cover your area but another organisation might -it would be worth looking. Papworth were invaluable in helping us understand the process.
Second, the form is trying to cover all possibilities for all disabilities for a wide age range, so some questions will just be irrelevant e.g. about school. Its totally fine to mark some as n/a. One helpful bit of advice we got was to think about the help dd needed over and above what most parents of a 2 year old give. Of course it can be hard to know if, as with us, the dc with a disability is your first child.
The other helpful bit of advice we got was not to think about a good day or try to average, but to start by describing a really bad day and then work out how often the bad days happen. You want to make sure you're describing the full extent of care required and not painting a rosy picture. This is something I think most parents find really hard, to focus on the negatives. The suggestion in the DLA pack of keeping a diary and noting e.g. how long it takes to get dressed each morning for a few days is a good one.
If your ds wakes 3-4 times every night, doesnt walk or talk then that is significantly more care than most parents of an 18 month old need to give - something that is becoming clearer to me now I have a second dc who isnt yet showing any signs of delay. I didnt realise that when we first applied for dd. I would focus on those questions in the DLA form, and describe his mobility in that section even though he isnt old enough to qualify for the mobility component, as it gives a fuller picture. Make sure to describe how his mobility, communication etc affect his safety in various situations. That apparently goes down well with the assessors, makes them pay attention. Also send copies of any reports you have from consultant etc, and appointment slips where you dont have reports.
I hope that's some help. Happy to try to answer questions, though may take me a few hours to come back. Or to talk about GDD more generally if that would help.
Hope you have a good evening.
PS - I work full time too. Good for you! Though it can be really hard to juggle can't it?