hello & welcome
i must admit, i did things your way in the past (i.e really low cals - tonnes of cardio) and in all fairness it does work to a point but you are really setting yourself up to make things tougher in the long run... after a while at best you will find that all that happens is the weight stops coming off... but what do you do then? worst case could be that you cut cals further/train harder and become run down/ill and end up laid up recovering (and probably gaining weight lol) - not to mention the higher risk of falling off the wagon due to general hunger!
realistically, with your size and with a good hours worth of cardio you could easily be taking in something like 2500 cals (maybe more) and still reach your goals IMO.
id drop the slim fast and add in some decent food - even something as simple as a tuna/mayo sandwich on wholemeal or something would be far better IMO... or if its a struggle with work (as it is for me) a liquid meal of whey and fine oats or something would be better than that rubbish lol - not to mention LOADS cheaper.
training wise, id say if your goal right now is purely to lose fat then what you are doing is fine.
you could also google carb cycling..... unless theres some info on here?? I know thats the way forward for me and it seems to work well for a lot of guys without the need to feel like your dieting