iptable rules for double chain vpn

I want to setup multi chain vpn using openvpn. The idea is as the following

Client ------- > VPS1 ------------ VPS2 --------- Internet

I have the following setup:

Windows PC Client

VPS1 Debian: Openvpn installed with 10.8.0.0/24 with public IP aa.bb.cc.dd

VPS2 Debian: Openvpn installed with 10.7.0.0/24 with public IP ee.ff.gg.hh

I tested the connection between VPS1-----> VPS2 and it's working fine. I do curl ifconfig.me and I get VPS2 public IP.

I have the following problem:

1. If I establish connection between VPS1 and VPS2, my ssh connection to VPS1 get disconnected and also client cannot establish vpn connection to VPS1

2. I want SERVER1 only forward the traffic of vpn clients 10.8.0.0/24, not all vps traffic.

I do research and I tried many solutions but not working, I don't know how to make SERVER1 forward vpn traffic to SERVER2.

Please help.