You ask a good question, because it really seems that someone who has been a miner for 5 years should mine a lot more than just 15 BTC, but the OP still says that he had losses on several occasions on scam crypto exchanges - although then it can be concluded that he lost almost everything given that mining was much more profitable at the time - the first 4 years the reward for each block was as much as 50 BTC. 

It is possible that he was also one of the victims of the greatest crypto tragedy Mt.Gox - but there may be a possible surprise for him, if of course he is among those who demanded compensation.