You need to sit down and TALK to your husband! Reassure him a LOT that he means the world to you. Explain NRE (new relationship energy) is making you giddy. Let him know that you are worried it might be too much for him to take. Ask him if there is something you can do to help him. Maybe schedule a 'just the two of you together' night when you get back where you give him a massage and pamper him. On your special night I would not talk a lot about how wonderful the new guy is.
This man has set you free! Surely the enthusiasm and giddiness you are enjoying is largely of his making and he deserves to enjoy the wonder you are feeling in a very special way!
Likewise, talk to your new boyfriend and advise him to likewise pamper his primary when he gets home. It sounds like you have something wonderful. But now is also a time to take care of your original relationships carefully.
Good luck. Warm regards, Rick.