Hello,
Firstly there is no "hummingbird" penalty. It is not a penalty, you got de-ranked because you do not meet the quality standards of the new algorythm to rank or your content is not good enough to deserver a high SERP. From what you explained, you are running microniche sites which depend on EMD...very well known story...1000 searches a month, low competitive keyword, £100 CPC minimum etc...correct?
You then bought bulk services on PR, comments, social signals etc from warrior forum, fivver, BHW etc and you ranked due to low competitiveness and EMD mostly, well know that these kind of sites can rank with few blog comment spamming even if they are no-follow links. You got hit because other web sites with similar content/niche have better content than you and probably people stay on their site more. Even if you remove the links you wont jump up on SERPS because you lack the content to do so and you also lack good quality links which you wont get by running an MNS.
The only way to get your ranks back is to focus on writing good content, have a top notch on page optimisation and forget link building for a while. Clean your profile with disavow that's ok but make sure you know what you are doing because you might kill "good" links (if you have any).
Hope this helps