I disagree with your statement in regards to "rubbish channels", either they are doing something which appeals to a particular part of the youtube "market" or they do sub4sub. have you sent a message to these channels, maybe get a collabration with them or network with them to grow together? Never look at another person's channel and compare it to your own, if they are "bigger" than you, why is that? work with them!
When I go to a channel, I don't check their sub count but what I do look for is 'how much each video is viewed and the feedback they get', that will give you a good indication what the channel is about.
Everyone has there down days, if you aren't enjoying recording and editting take time out, if you persist through it because "you must upload" you will just burn out and quit, this happens all the time when people do something they don't enjoy. real life example, if I'm having a bad patch in work and struggling to motivate myself, I take 2 days off and do something I enjoy and be with my family, this powers me on! the result being, my productive increases and my work is better for it.