Your story is not unique and of such important character that only you have to find the answer within you.
I might help by asking you some question, and give some thoughts, and I recommend that you think it true in a calm situation.
First of all...try to think back when you first fall in love with your husband....is those feelings you felt then much worse then what you feel for the new one?
You have now lived with your husband for 15 years, you both still love each other, and since it has been so a long time...I assume you both also respect each other, else no love would last.
When 2 people join together, then it is 2 free wills that have to find a golden way between ones own demand and the couples demand, you know how your husband deal with this....you don't know how a new one will...is your situation so bad that any improvement in one field will be enough to get a richer life, are you sure he will have the same qualities that you like in your husband?
You are saying your husband don't fulfill you spiritually.
When 2 people have lived together for 15 years, then it might start to be a humdrum everyday occasion.
If feelings of "defeat" or lack of excitement is allowed to grow, then those feelings will soon destroy a good marriage.
It is in both interest that such feelings are "killed" as soon as possible...and the only way I think you can manage it is to take a discussion with your husband.
Put up things that you want him to change, be honest and calm...be also fair and ask him what he want you to change...try to get excitement back into your life.
You are both still young, and if you both love each other, well then the marriage is worth fighting for, but one need to take initiative and not only let it die.
The fact that you have met someone else and feel that you can love him are no surprise.
If your day feel to be dull, well then any situation that can give excitement will lead to thoughts about a better life....but sorry to say....they will also be corroded by time and again we will change into this old habit of "dullness"
I wish you good luck with your decision!
