In my opinion, your guilt seems to stem from your past boyfriends being jealous of you talking to other guys. It feels wrong because your past partners did not like it, this conditioned you to feel guilty for confiding in male friends.

You aren't doing anything wrong. If you feel like you're "hiding" something because you're talking to a guy about relationship advice, tell your boyfriend now. It's hard to keep "secrets" because the later he finds out about it, the more it will appear to him that you actually were hiding something from him the whole time.

If he can't handle it and tries to get you to stop talking to your friend, that is a sign that he is going to control who is and isn't in your life. You can re-evaluate your relationship with him.