Marriage... Love... Society...
Do you notice how messy your situations have turn
out to be? It didn't born this way - you made enough foolish
choices to transform it that way.
Here's a huge thingy for your consideration: Do you think your
liking for S is 'Love'?
You mentioned there wasn't any mote of feelings three years back;
it was ONLY after you went through your wrecked marriage, had him
to be there for you, with him declaring his actual feelings -
before you grew to like him.
Don't you see this MORE like a passing-by 'rescue boat', instead of
'Love'? Especially your marriage began to get abusive?
How do you think it will be different if he never reveal his
feelings to you? Or if there was never such a thing?
IMHO, this is an important variable. 
***
I hope you do see yourself going through a series of
crisis because, you ALLOWED circumstances to drive your options and
churn out a load of chaos as a result. Being passive serve much
reason for your plight as well; other forumites calls it the lack
of courage, but I reckon it to be passiveness. Lack of courage
means you DESIRE to do something strongly, but LACK the strength to
implement (E.g. chasing a girl). Passiveness refers to the
non-chalent, easier-on-emotions-route to undertake, which
ultimately goes nowhere and probably end up in Limbo. You may even
have opportunity placed right in front of you to leave, but
opportunity is still often left untouched, while a lack of courage
with correct opportunity would be grasp immediately. It is easier
route because it buys you some time and wouldn't create much
changes to your exisiting situations (People often resist changes
and if you want to implement something, big changes are bound to
happen). It is so much easier, say, if you were to remain in your
marriage (appease your parents), suck all your dis-satisfaction
into your mind (appease husband, fear of psychological affecting
child-upbringing), etc.
You may not realise, you may have subconsciously chose to maintain
in the relationship, despite finding no Love in it... just for the
sake of it - whatever it means to you. To some, it could be the
length of time together... your baby... society's bondage...
parental influence... and all other external factors.
There are many people out there remaining in unfulfilling
relationship for reasons other than Love. They often lament about
how CMI their relationship is, but you still see them clinging onto
their relationship, which makes many wonder why.
No... the fact is that it is they who chose to
retain their relationship. Nobody else did...
nobody else HAD the power, regardless of how you thought others
might have the power to do so (This is the Second Law of
Love).
***
I believe you have already decide what you want to
do and I am not doing to change what you had already plan for
yourself. I just want to offer my thesis to complement your
self-reflection.
Actual Love or not... you decide. Once bitten twice shy? Will you
exercise more wisdom in your decision? Or would your continue your
foolishness even further? Marriage is never a game nor gamble - it
is the fruit of a fulfilling relationship, awaiting to blossom
beyond its boundary and reach for the sky.
Cheers
