Since you are playing on EXPERT mode that means that all NPCs (INCLUDING YOUR FOLLOWERS) will be better than you. According to the UESP, the difficulty level affects the damage you deal and the damage you receive:
This means that your followers deal 1.5x more damage than you, and they only take 0.75x as much damage. This is the downside of playing at higher difficulty levels. You might want to consider using mods that increase battle difficulty without having to increase the difficulty mode. For example I use Deadly Combat, Combat Evolved, ACE, and Fighting Fatigue.
*Edit* Another option would be to use a follower mod that allows you to specify how strong your followers are. For example I use AFT and it allows me manual control over the health, stamina, magic, and stats of my followers (assuming those followers are in the standard following system; mods that add followers like Vilja and Inigo 2.0 would be an exception to this).
@Aiyen: THANK YOU. Yes using the ENB shift-insert finally did the trick. I was pretty sure I had tried that before without success. But now the screenshots look just like my game.
*edit* still seems just a tad too bright. lowering the brightness in a picture editory just a bit helps.
Glanzer's post in followers stronger than me ! was marked as the answer