Dior definitely seems to be the way forward.
You might also consider dressing for a slim guy (Items such as double breasted suits, slim fitting trousers) but accentuating more feminine details such as a light scarf or very heavy and high waist suppression. Mens tailoring is essentially about structure and masculinity while women's is about shape and femininity; look for items with more of a shape to them in menswear to achieve a bridge.
Also try searching for the user Uncontrol, he is mockingly referred to as "Angry Transvestite" as many of his casual looks appear to achieve the look that you're going for without necessarily intending to.
I would also second the Preppy look, examine the look-books of UK companies such as Jack Wills and Fat Face for ideas, as well as Polo Ralph Lauren, Gant and many others. That should cover you for casual wear. With regard to formal; Dior Homme is great for super-slim guys like you - and while not overtly feminine, they have an air of elegance so more Oscar Wilde than Elton John. If you're looking to go MTM then look at Thick as Thieves, who disappoint many by cutting too thin for "normal" people to wear, but would suit you down to the ground. Also, you're young so while it may not fall in line with the folks here, look at people like Pete Dougherty for tips - his hyper-fashion mixed with heroin addiction makes him skinny-cool.
On a side note: That was the most deft handling of a troll I've ever seen. You Sir are awarded the Freedom of the Internet