Hello Jaffer and welcome to the forum, and thanks for the compliments (all true by the way)!
0.5kg is ok for a start, especially if you took the 'eat what you like on a feed day' the wrong way! As you get more into 5:2 you will probably find it starts to modify your eating on your feed days as well as your fast days - and the advice on the forum here helps with that too.
Although the 5:2 prescription is very simple indeed and doesn't require any dietary change apart from the calorie limitation on the 2 fast days, it does make us more aware of what makes us hungry and so that can change what it is we want to eat. I've learned a lot here about what is good to eat (and what is not), and it's definitely changed my overall eating habits. See this
currently active topic.
Do consider putting your numbers into the Progress Tracker here - you get a nice graph as a reward and an incentive to further weight & waist loss, and you contribute to the overall forum stats which are also interesting to study if you are a bit nerdy like me. One statistic that comes out of them is that average weight less is a tad under 0.5 kg - so you are doing fine so far!