Impacted ear wax is no fun.
The first thing to do is STOP using cu-tips. I have never had a health professional suggest to me that they are useful cleaning tools. The design of the things will always push wax into your ear. All you need is one ambitious push with one of those to put wax where it doesn't belong.
If you want to clean out you ear, the following has helped me in the past.
a) while in the shower, allow water to spray into your canal. Gently massage the area between your jaw and the back of your ear. Gently pull your lobe down while water enters. Allow water to drain out naturally (daily maintenance).
b) using a dropper and a 50/50 solution of high strength alcohol (I use 90%), and ordinary vinegar, tilt head and place 5-6 drops into the affected ear. Remain tilted for thirty seconds. Then, put head upright and allow to drain naturally. This is both useful disinfectant, and a good wax softener (if you buy ear stuff in-store you will find they usually contain alcohol as a main element). It can burn, but so far hasn't killed me.
Repeat the treatment up to maybe 3 times a day, but be patient - the wax is being softened and will make its way out. Use NO cu-tips to dig it out. Stick to shower / drop treatment.
When impacted, it can take a few days to go back to normal. In the mean time, avoid using your headphones at all - you will have a "channel imbalance" and blame the Amp manufacturer. But seriously, I think HPs heat up the ear, soften the wax, and can cause build-up. I sometimes listen (at low-mid volume) for hours a day, and noticed that I have to take days off at a time. The HE-400 sometimes create a lasting fatigue I didn't experience with my Sennheisers.