Fellow Aussie here who went through the discovering she has it herself at the start of the year (my nephew has it, bro ended up suggesting it after physio had said I was hypersensitive to pain. Suddenly my world made sense!).
First thing - good on you for looking further into this. Sometimes it can be hard to get people to accept help and that change can happen, but the more information you're armed with, the better.
Second thing - it's hard to get your head around the diagnosis. When you've been living with this all your life and suddenly somebody goes 'oh, it's not just that you're odd, there's an explanation for it!' it takes awhile to process that. There will be anger, sadness, introspection. Frustration that things could have been different. Your husband will likely go through this process. He's probably also feeling a lot of frustration with himself that these things do effect yours and your childrens' lives as well.
Cost - actually not that bad in Australia. You'll need to get your GP to refer you to an Occupational Therapist - they're the people who make the diagnosis and will be able to provide intervention/management skills. This website:
http://www.otaus.com.au/ is the list of OTs in Australia. Go to the find an OT link at the bottom, speciality sensory integration, and look in your area. Hopefully there will be some OTs that come up. Ring around, see who diagnoses/treats SPD in adults and is taking new patients. Once you've got a name, then you can see your GP, bring along info about SPD with you (a lot of GPs have never heard of it), and get a referral.
Now, when I first called my OT the cost she quoted for the first session was higher than the rest by a fair bit. That was because mostly they do a full written report on you from the first session which adds on greatly to the cost. In my case, I really couldn't see the use of having it (more useful if you need to have something for a workplace or if it's your child for school), so my cost jumped back down to the normal session cost of around $120 (will vary from OT to OT), with getting back some through my private health care.
The OT can provide a variety of intervention/management skills and ways to think about things to minimise the issue, and how to create a sensory diet. For me, the brushing protocol has been one of the best, as well as starting yoga. I haven't had a huge number of sessions with the OT as she's given me a lot to help me get through day to day life.
If you have some hard facts/numbers to give your husband, showing that it may not be so bad cost-wise to look into this, then he hopefully will come around. But do give him some time. It takes time to process through everything. Another really good help can be Sharon Heller's books. She has a new one out (there's a post about it on the forum) but also the book Too Loud, Too Fast, etc. I found really useful for understanding what was going on with me.
Also look at other posts on here, people posting about their own journeys.
Finally - I know this hasn't been easy for you. Hopefully with time things will get easier.
