Divide public network into VLANs. I it possible?

Hi. Asking for an advice.

I have received several \24 public networks from my ISP.
They come to eth1 port. Eth1 port is bridged port with Eth2. Port eth2 is connected to the switch, trunk port. Other ports of this switch are in access mode, native vlan. To switch connected end-users using ISP gateway and one of ip from network. Everything works fine.

All networks are in NATIVE VLAN.

I need (if it is possible), to divide part of one \24 public network in separate vlan (for example vlan 2). How can i do that, i guess that i should add this network (for example \29) to the ip addresses section , put it in vlan 2 and user router ip as gateway on end-user machine. Of course change access port of end-user to vlan2. I have ping on gateway, but I have no access to global net.

I would be very appreciated if someone explain how to solve this problem or tell me that it is not possible. Thank you.