so I'll put the interface config and the NAT config of the thing I used, just noting that I have one DSL WAN internet connection and another Fibre on VLAN 2370 on ethernet port 12 so I have two.
/interface bridge
add fast-forward=no name=bridge1
/interface ethernet
set [ find default-name=ether2 ] name=DSL~WAN~E2 speed=100Mbps
set [ find default-name=ether1 ] name=LAN~E1 speed=100Mbps
set [ find default-name=ether3 ] name=Tamreed~E3 speed=100Mbps
set [ find default-name=ether5 ] speed=100Mbps
set [ find default-name=ether6 ] speed=100Mbps
set [ find default-name=ether7 ] speed=100Mbps
set [ find default-name=ether8 ] speed=100Mbps
set [ find default-name=ether9 ] speed=100Mbps
set [ find default-name=ether10 ] speed=100Mbps
set [ find default-name=ether11 ] speed=100Mbps
set [ find default-name=ether12 ] speed=100Mbps
/interface vlan
add interface=ether12 name="vlan 2370" vlan-id=2370
/interface bridge port
add bridge=bridge1 interface=LAN~E1 trusted=yes
/ip firewall nat
add action=masquerade chain=srcnat
add action=dst-nat chain=dstnat dst-address=RealIP dst-port=80 log-prefix=OSS protocol=tcp to-addresses=192.168.0.9 to-ports=80
add action=dst-nat chain=dstnat dst-address=RealIP dst-port=80 log-prefix=OSS protocol=tcp to-addresses=192.168.0.232 to-ports=80
add action=dst-nat chain=dstnat dst-address=RealIP dst-port=80 log-prefix=OSS protocol=tcp to-addresses=192.168.0.12 to-ports=80
add action=dst-nat chain=dstnat dst-address=RealIP dst-port=8818 log-prefix=OSS protocol=tcp to-addresses=192.168.0.16 to-ports=8818
add action=dst-nat chain=dstnat dst-address=RealIP dst-port=1433 protocol=tcp time=0s-23h,sun,mon,tue,wed,thu,fri,sat to-addresses= 192.168.0.120 to-ports=1433
and when I tried the NAT config you advised and it either breaks the internet connection in the ORG or doesn't show the source real IP it shows the Router's IP.
I attached the NAT screenshot that breaks the internet also (bear with me I'm not that of an expert in Mikrotik)