Several suggestions:
1. I prefer muffs over plugs. Good muffs (not the ones you usually get at indoor ranges) simply work better for me and provide better protection than plugs. But, you could use plugs and muffs together. If you are wearing muffs and eye protection, make sure that the eye frames aren't interfering with the fit of the muffs around your ears. I personally have a hard time getting plugs to stay in my ears, and I get concerned about wax compaction - not fun!
2. You are going to have to get used to the noise, unless you have acreage out in the country to set up a private range. And, it's not just the noise to the ear - it's the concussion you feel when someone is shooting near you. The best thing you can do is spend more time shooting in the vicinity of other shooters. Believe me, you will get used to it, but you need to spend the time - not just 1/2 hour every 6 months.
3. This next bit of advice will sound really stupid - but there's something to it. If possible, try shooting a pistol that is fairly loud and somewhat powerful - louder than those generally around you. That would be .40 (or 10mm) out of a rather short barreled pistol; .357 from a revolver. You don't need to go extreme, i.e. beyond these cartridges, if you don't want to. But, once you've put half a box through one of these guns, the report from other guns won't bother you as much.
4. Or, take up archery. I'm not being sarcastic - I really enjoy the quiet, precision and physical aspect of shooting my bow over a rifle. I still like shooting pistols and Skeet, but have moved away from shooting my rifles.