What does an asthma attack look like? And how long does it last?

My son is ten months old and has asthma. I just took him to the doctor yesterday for his asthma. He is on a quick acting inhaler and a preventative inhaler. When I took him to the doctor she said he had croup and an asthma episode which is causing his lungs to spasm. He had already been on his inhalers three days prior to me seeing her, but her advice was to continue with the inhalors and come back if he's in an acute attack. Anyhow...I made another appointment for him today. He seems to be getting worse and the inhalors aren't providing any relief. In the meanwhile...I was wondering if he is having an attack. All last night he kept waking up and coughing and whimpering. His energy is low and is breathing is labored. His tummy goes in a lot when he breaths and he raises his shoulders. However, he still smiles at me, but looks very uncomfortable and lays his head down on me a lot. I layed him down in his crib and observed him. He was just laying there staring at me and breathing heavy.

How can I tell how distressed he is. It's confusing because he looks so very uncomfortable, yet he still smiles at me.

Hiya
He smilesbecause he is looking for his mum to reassure him. Heavy wheezy breathing,lethargic, uncomfortable and using his shoulders sounds like he could be having an attack. You know him best and know what he is like and if u think something is wrong then take him to the docs and don't let them turn u away until u are happy. There are so many different treatments for asthma now they should not be leaving him uncomfortable

He is smiling to comfort you, it is apparent to him that you are distressed. Just like when you try to calm him you smile and talk sweetly to him.
It sounds like distress to me. I would call and see if they can see him today, if they can't see if they recommend taking him to urgent care or the ER.
Sorry you both are suffering. I hope for the very best. :)