Initially, congrats on the weight loss. Losing 45kg is nothing to be scoffed at. I don't know the time frame of the weight loss, so I assume your growth in height had something to do with it. But still, that's a great amount of weight to lose. If you have the dedication to lose all of that weight, you should be able to put up some big numbers, considering your level of commitment.
You're the perfect candidate for GOMAD -> within the age range of 16-23, underweight, 6ft 1 (and still growing), slightly underweight.
At 86kg, you should not be failing a sub 60kg bench press. Read this article ->
The First Three Questions | Mark Rippetoe
Under 3000 cals per day for a tall, slightly underweight 16 year old is far from optimal. You should be taking in at least 5000 cals per day for roughly 2-3 months until your bodyfat percentage becomes an issue, where you can scale your calories back. I also suggest reading this ->
http://startingstrength.com/articles...n_rippetoe.pdf
With regards to the lack of appetite, I'll give you my experience. I recently had very stressful college exams where I wasn't eating any food (only getting 1.5-2kcals per day). For the week following my exams, I stayed up pretty late (sometimes until 2-3am) finishing my last meal so I would hit a certain amount of calories for that day. It was tough, but now my appetite is back to normal. I cant stop eating. I went from 104.4kg to 112.5kg in the last 20 days. I probably overshot my calorie mark on a few days, but, as I said, I have no problems with my appetite, I'm setting PRs in the gym and I have a lot of energy.
Good luck