how do i get exotic matter and how can i get more ?????????

You get it in mineral shipments.

The bigger the shipment, the more you get.

thanks

you can also trade and buy some

Most effective way to raise mining production is to go after toxic planets and farm lot of NPCs for purifiers then irradiate them later (if toxics are 15x or 16x first). Put Mylarai Stripcore Mine on those toxic planets because they are best for it cuz you don't need its artifact resource so its ok to render it useless.. Be sure to put assimilation locuses immediately on those toxic planets if you invaded them.. Then you will start to enjoy seeing nice mining production.. They are all doable very easily rather than hoping for a Dyson or Exotic or anything like that..