I cross posted with you. Practical advice.
Children's social services. Ask for an assessment for your daughter and also for yourself as a carer.
Do you get Disability Living Allowance for her? If not look into that. It's a horrible long form though.
Look for the 'Local Offer' for children with SEND on your local council website. Ring some up and find out how you access them. They might be full up now but still ask how to access them for the future. You will probably need a local.authority assessment.
If your child has a particular diagnosis, look at national charities for that condition. They may have a local support group. Even if it's not very local they may be able to point you in useful directions.
Your local authority or area probably has a parent partnership group run by parents of children with SEND. (I don't mean the one that helps you at meetings.) My local one is very good and organises its own meetups, and publicises other SEND-friendly activities that they don't run themselves, eg the local football club running SEND sessions.
Once you have found an activity, go along and talk to other parents, because they are a wealth of information and one thing leads to another. For example I used to take my son to an adventure playground session and learnt about swimming lessons from another parent.
Is there a parental involvement teacher at DD's school? Talk to them. If not, talk to the Senco.
And crucially, keep going until you get somewhere. Good luck.