I am convinced from what you have posted that your husband is depressed.
Depression can take away all that is positive in feeling and replace it with all that is negative. The love doesn't go, it just feel like it does because you can't connect with that part of yourself.
He will be feeling pretty terrible and also pretty confused. I am sure he does love you, but it is just that he is in 'no-mans land' right now. Where he is he will be very likely to withdraw from you.
When a person becomes tearful like that - depression is usually quite severe. If you describe stomach problems and sleeping issues that have been ongoing this might have been building for a while.
He will be thinking "she doesn't make me feel the same anymore" and it is easy to mis-interpret this that your feelings have changed. "I love you but I am not in love with you" is a hallmark expression from depressed partners.
This is hard on him but it is also going to be hard on you. It is treatable, but it is also quite slow to treat and many people are resistant to admitting they have a problem. Most depressed people believe their thoughts (why wouldn't they?) and this can be very dangerous in a marriage.
Can I please advise you to please ask him to see a doctor. This might be hard, but if you tell him you believe he has "stress" and that doctors can really help with this he might be more inclined. Anti-depressants can come with their own bevvy of wonderful side effects (a common one being numbed emotions which won't help!) but if he is very depressed they can help him find a stable platform.
He must get counselling. This is going to be a hard sell - it often is. However people do not get depressed usually "just because" they are stressed. There is usually something fundamentally underlying that combines with stress and isolation to create depression.
Unravelling this is the best treatment. He may have repressed past hurts, emotional issues, difficulty expression his worries, childhood pain...a million things -but there is always a path that leads there.
I want to offer you some support now because when your husband is depressed it can be soul destroying. Your once loving husband might withdraw from you, he might tell you he doesn't love you, he might be completely unable to empathise with you, he might start talking about divorce, he might get aggressive and it's not even uncommon for him to look for someone else very quickly (to try and make himself feel something).
Can I recommend a book called "Depression Fallout" which you can buy on amazon and there is also an online support forum for partners with depression. PLEASE joint that forum as it saved my life going through the same experience as you.
Please also look at a book called "Depressive Illness, Curse of The strong" and "Undoing Depression". It would be wonderful if you could read this with your husband if he is willing or able but remember right now he is not himself.
Please keep posting OP. I have been where you are and sadly my husband left a perfectly happy marriage and behaved very badly when he was depressed and we were not able to recover our marriage. I really hope for you that you can take steps to address this pro-actively now but believe me when I say it is not easy.
Sadly my husband became s convinced he did not love me that he left out home and got his own place and began divorce proceedings. I did everything I could to stop him, but unfortunately by the time he realised he was depressed and his feelings came back too much damage had been done.
God bless OP
x