Dairy and egg free breastfeeding mother here too!
You need to take a supplement yourself of calcium and vitamin d to avoid problem later in life (bones, teeth etc)
DS will be getting calcium through your BM, another good source is ready brek/smooth porridge-if you can buy oatly barista (foamable)- grey carton this is equivalent to blue top cow's milk- make it up with this.
Use alternative yoghurts/cheeses that have been fortified with calcium-my DS likes koko-you can get these in Tesco.
Do not use goat or sheep milk as a sub as this is too similar to cow's milk.
Vitalite is vile IMO, pure spread is much better.
For yourself, choc chip hobnobs and own brand Jaffa cakes are usually dairy free.
On Facebook there are a number of CMPA support groups- CMPA support for weaning and CMPA support for breastfeeding- these are great for any queries you have and just generally browsing when you're hungry and trying to work out what you can eat!
In terms of eating out, nandos are great, pizza express, zizzi and pizza hut all do vegan cheese too!