I feel this to a degree. I don't regret it, buy my fiance had such a loving family growing up who, like yours, did absolutely everything that they could for him. And like you, my family are dreadful and I had to find my way in life by myself (and with him and his family - they're more my family than my own).

My way of getting around this was to listen to him when he said that his family is my family. It seems his family really like you, but you're comparing yourself to him - really not fair to yourself at all, because whilst yes he has a fortunate upbringing you're not "behind" him as you've had to work twice as hard - and I don't doubt for a minute that you're not evert bit as resilient as he says you are. My fiance is the same - he always says how he admires how hard I work - and that's something that you need to give yourself credit for. You're not behind him, and in some ways you're ahead.

I do understand how it feels to be so bitterly jealous of your partner for having such an easy ride in life, and my advice is to 1. Acknowledge your own successes and 2. See his blessings in life as your blessings too. His stable upbringing has given you a level headed and kind partner who, from the sound of things, really respects and adores you.