That is indeed a high loading time, even for IE11. Here is some advice. I will start with the basics based on your performance review from wpt:
first bit time is high: consider better hosting. That’s all I have here. From all the CDNs I believe cloudflare is the only one that can improve this metric.Also, Apache is pretty good nowadays for a webserver, but consider nginx + php7 as your next choice to get some extra speed. If you are using wordpress, easyengine or serverpilot (google it) are a good way to set up your sites. I recommend learning to configure nginx.
consider using a CDN. Cloudflare is free but you have to pay to use your own signed SSL . KeyCDN is cheap and decent. It offers the possibility to add your own ssl or use letsencrypt(free ssl) which is a decent option (I use it myself).
Compress Images : I assume you use Wordpress? You can find a lot of plugins that can do this for you. If you don’t please use a free service, we have plenty on the web (google compress images). On the topic of wordpress, you should consider using total cache or super cache or rocket wp if you can afford it.
Recommendation #1:
As the previous response by zamolxes suggested, please consider using a better hosting or a CDN. You are losing about 3 seconds in the initial redirect from www.abboko.de to abboko.de and the subsequent loading of the HTML. When you use a CDN, the redirect can be issued from a node closer to end user and the latency involved in the request/response will reduce.
Recommendation #2:
Apart from that, you could consider lazy loading the web-fonts. If you see the waterfall, requests # 9-18 are all webfonts. While working on you, you could consider if you really need all these fonts! Maybe reducing the fonts would also help the performance.
Recommendation #3:
Refer WPT: http://www.webpagetest.org/video/compare.php?tests=160330_Y9_X3V-r:8-c:0
If you look at the film-strip view of your site, you’ll notice that some text loads first at 6s. At 9th second, this vanishes and is replaced by the content that is shown in the viewport.
My suggestion would be to prioritize content that is above the fold. This will also mean that you could try to lazy load the product image, if that is not already being done.
Suggestion:
Your WPT test run was from Dallas, USA. I guess your end users would in Germany / Europe. In that case, I’d recommend trying a WPT agent from within these regions so that you can get a more realistic experience.