Internet Facing load balancer infront of 2 private instances

I am trying to setup 2 web instances in a private network and put an internet facing load balancer infront of my two instances.

This is what i want to achieve:

1. The 2 private instance should be able to access resources on the internet. But the internet shouldn't be able to access the instances directly.

2. These 2 instances should only be accessible via port 80 from the load balancer from the internet.

The reason why i want to do this is because i don't want to expose these two servers on the internet.

1. So i've created a VCN with CIDR block 10.15.0.0/16
2. My two private subnets are 10.15.1.0/24 and 10.15.2.0/24 respectively.
3. My public subnet is 10.15.100.0/24
4. Instance A is hosted on private subnet1 and Instance B is hosted on private subnet 2
5. My Network Load Balancer is hosted in the public subnet.
6. I've added a route in my public subnet that routes 0.0.0.0/0 traffic to my internet gateway
7. I've added a route in my private subnets that routes 0.0.0.0/0 traffic to my NAT gateway

In the route table for subnet1 i have added a route to InstanceB

In the route table for subnet2 i have added a route to InstanceA

In the route table for public subnet i have added both a route to InstanceA and InstanceB

I have nginx hosted on both Instances.

From the instance i can ping 8.8.8.8 but from the outside i can't access the webpage using the load balancer's public IP.

A telnet to public_ip 80 works fine though. I tried to access the webpage from a browser and even did a curl but no success.

Is there something i did wrong ?

P.S i am doing these in OCI cloud