Being a bit possessive is not a bad trait. Obsessing and thinking your BF is/would be doing something behind your back is destructive to your relationship. Never having any straight friends except his straight friends is a bit unusual and I'd advise you to respect boundaries and encourage the others to respect them too. That's all you can do and hopefully things will sort themselves out over time. The relationship is only just a year old and it should be growing for the rest of your lives if you nourish it and each other.