So had posed my model for a key frame and got side tracked. When I came back for a moment I hit Apply on the Armature and then saved and shut down the computer.
When I came back I realized that I should not have hit the apply button because now I can’t pose the model anymore…
Hopefully you saved an earlier version that you can revert to. If you’ve turned on versioning in your user preferences you should have a .blend1 file which is the last time you saved the file before the most recent save. Hitting Apply on a modifier makes its changes real, and if you have a posed model it isn’t going to be easy to un-apply now that you’ve saved and closed.
If you haven’t moved the armature or the model or deleted the vertex groups you should b able to carefully reconnect the mesh to the armature by first making the pose the rest pose, and THEN giving the mesh an armature modifier with the armature specified. Don’t use the ctrl-P parenting procedure!
Maybe you could upload the file before doing anything else and we can see if this is a practicable thing.
In theory applying the modifier should not have damaged the weighting in any way.
If you posed the model and applied the modifier then the base model has been reshaped, probably asymmetrically. That pose is no longer an armature deformation; it’s the shape of the mesh now. Even if you do re-attach it to an armature it will be screwed up because you are deforming a model that is a completely different shape from the rest pose of the armature.
Like I said, I hope you have a backup of an earlier version of this model. Otherwise you’re going to need to do some very tedious manual work to reshape your model back to what you want it to be.