It does look like your relationship with your husband is troubled, and you seek things from your boyfriend that your husband doesn't give you (caring, for instance).
Now, that doesn't really mean anything. I mean, the fact is that you're with both of them, want to be with both of them, love both of them. So work on the relationships so they both make you happy independently.
And if your husband doesn't treat you right, stand up for yourself. Suggesting that letting you cuddle with him is a sacrifice or a payment on his part is outrageous. He needs to treat you with respect.
As for being slutty, I fail to see why it would be a problem (if you want sex and you seek it and don't hurt anyone in the process, how does that make you a bad person?) but in your case you were seeking emotional comfort with your boyfriend, so it's not even about sex and being horny, so I'm really not sure where this comes from.