Unable to downgrade Xorg

Hello,
I ran into a problem where my AMD drivers does not work with the Xorg version 1.18. To fix this I am trying to downgrade Xorg.
To do this I tried typing:
cat /var/log/zypp/history | grep xorg-x11-server
into the Konsole to find the version I was using
The output was:
2014-10-26 09:07:24|install|xorg-x11-server-extra|7.6_1.16.1-2.1|x86_64|root@opensuse|InstallationImage|941cbbc3c10d56ec21c683eb0b34a3ad8cd5aefc255ce9530e31f8992ee8c80f|
# 2014-10-26 09:07:34 xorg-x11-server.rpm installed ok
2014-10-26 09:07:34|install|xorg-x11-server|7.6_1.16.1-2.1|x86_64|root@opensuse|InstallationImage|e157d2e5d7cc3e33a0eab72f0eb6cfb6bdb7b8909caabdeae53076484b054bc3|
2015-01-01 16:32:41|install|xorg-x11-server-extra|7.6_1.16.1-5.1|x86_64||repo-update|2f8ef3d047ab43da83bf26b116f1264c81f906fe130cd2dc4e101da84ff8be0d|
# 2015-01-01 16:33:24 xorg-x11-server-7.6_1.16.1-5.1.x86_64.rpm installed ok
2015-01-01 16:33:24|install|xorg-x11-server|7.6_1.16.1-5.1|x86_64||repo-update|f15058bd4731e84bed599698fe8545dd056205a50f3e7c4fb23c31427787ff86|
2015-04-17 21:31:38|install|xorg-x11-server-extra|7.6_1.16.1-13.1|x86_64||repo-update|2add3dc1497cf79fe5d068d35d3ea7790ec16739334b3c14026abe4b1a3f24e8|
# 2015-04-17 21:31:46 xorg-x11-server-7.6_1.16.1-13.1.x86_64.rpm installed ok
2015-04-17 21:31:46|install|xorg-x11-server|7.6_1.16.1-13.1|x86_64||repo-update|64c864ae65502f7be92978c8d2d4abeee57535d5ed1dd9aa0b38a7056d317eec|
2016-05-15 14:27:58|install|xorg-x11-server-extra|7.6_1.18.3-1.1|x86_64||repo-oss|f52373cfbcdfd06807b408edb706f73a762c086b|
# 2016-05-15 14:28:56 xorg-x11-server-7.6_1.18.3-1.1.x86_64.rpm installed ok
2016-05-15 14:28:56|install|xorg-x11-server|7.6_1.18.3-1.1|x86_64||repo-oss|dfb67320c14e32b999d579d8f98d75e7c4c8479c|
2016-05-21 13:47:10|install|xorg-x11-server-extra|7.6_1.18.3-3.1|x86_64||repo-oss|6f8beea3b3d8c75c878f9a1a53724ec38c5b4520|
# 2016-05-21 13:47:11 xorg-x11-server-7.6_1.18.3-3.1.x86_64.rpm installed ok
2016-05-21 13:47:11|install|xorg-x11-server|7.6_1.18.3-3.1|x86_64||repo-oss|7d794c899b02035159b2095e09963ea91d7a012a|
2016-06-05 13:39:21|install|xorg-x11-server-extra|7.6_1.18.3-4.1|x86_64|root@Kaladin|repo-oss|5713a6f7b264187949282bcad1bd85f6ec9c7fd9|
# 2016-06-05 13:39:40 xorg-x11-server-7.6_1.18.3-4.1.x86_64.rpm installed ok
2016-06-05 13:39:40|install|xorg-x11-server|7.6_1.18.3-4.1|x86_64|root@Kaladin|repo-oss|fd2a1c72fc6156cb926941b9212de6bb2ae9b416|
2016-07-31 07:38:54|install|xorg-x11-server-extra|7.6_1.18.3-4.2|x86_64|root@Kaladin|repo-oss|624c120720cf823f30f0f221484c5600e2ca0ae8|
# 2016-07-31 07:38:54 xorg-x11-server-7.6_1.18.3-4.2.x86_64.rpm installed ok
2016-07-31 07:38:54|install|xorg-x11-server|7.6_1.18.3-4.2|x86_64|root@Kaladin|repo-oss|48d98f1b67a95d755757b24b36ebf1abc0b52d20|
2016-08-01 19:37:11|command|root@Kaladin|‘zypper’ ‘in’ ‘xorg-x11-server’|
# 2016-08-01 19:37:14 xorg-x11-server-7.6_1.18.4-1.1.x86_64.rpm installed ok
2016-08-01 19:37:14|install|xorg-x11-server|7.6_1.18.4-1.1|x86_64|root@Kaladin|repo-oss|a7aee58c7e2e5ea4d34c8f5417e44f2737f4725b|
2016-08-01 20:08:25|install|xorg-x11-server-extra|7.6_1.18.4-1.1|x86_64||repo-oss|8b40b60f1b3dbcb30e4147e60510df75cf7532ad|
Seeing as the last version I used before 1.18 was ‘7.6_1.16.1-13.1’ I typed
sudo zypper in -f xorg-x11-server=7.6_1.16.1-13.1
It responded by saying

Package ‘xorg-x11-server=7.6_1.16.1-13.1’ not found.

Any help would be appreciated.

Tumbleweed is a rolling distro, so that old packages are REPLACED by newer ones in the repositories and you cannot downgrade as you would do e.g. in Leap.
If you are using the default install with BTRFS, you might still have a snapshot taken before your upgrade.
If so, you might be able to boot from that snapshot (see “Advanced Options” at the GRUB menu), lock the Xorg packages in Yast so that they don’t get upgraded, then perform a “zypper dup”.