Thanks for the answer, Vladimir. Although it does not sound too optimistic, it makes sense. However, I would really like to push myself as much as I can while I'm still in my early 20s - I'm 22 now. And I see some hope, for example a week ago I met a DoP, just graduated film school, and now he's called almost every other day to shoot commercials, corporates, etc. And in the UK, pay is pretty high for this sort of work. I am not expecting to earn millions from cinematography, but I would like to at least get to the level of being able to support myself (and my "future" family at some point) with it. Because I am passionate about it, I am motivated to work my a*s off and accomplish something with this.
That's what I'm trying to do at the moment - a bit more networking and asking around and looking for anyone that might need a DP for a project even if there's low/no pay.. However, I am often being asked if I own any lights and when I say they need to be hired this happens to put people off somehow. Maybe because they think this pushes costs too much or for some other reason. To me it makes more sense renting but I guess at the level of low budget or even no budget filmmaking this does not sound too good to people.