Am I the ass?

HELP!! I have to make a decision within the next few hours and I need opinions on if I’m being irrational or not:

So, my family is going camping this weekend. It’s with my grandpa (who I don’t know very well) and my parents, brother, and his gf. Now, I was a little nervous about camping with my grandpa and his daughter because we’ve never spent any time together so I thought it might be awkward, but I was still going to go. Then this past week has gotten EXTREMELY smoky from the California fires and other fires around my area. We couldn’t see the mountains around us for days and even though we can see their outline this morning so it’s a little better, it’s still crazy smoky.

Now, my husband has asthma and he keeps telling me how hard it is to breathe because of the smoke. He wanted to not go with my family for the weekend because we’d have to sleep in a tent so we’d basically have no protection from the outside air and he didn’t want to risk an asthma attack. He suggested we drive up the next day and spend all day there and then we can stay if it’s ok and if it’s not we can drive home late evening.

My mom flipped out about this. She said the only reason we’re not going is because I didn’t want to go and that I’m using his asthma as an excuse. She said she heard me talking to my dad about how I was worried it would be awkward with my grandpa and THAT’S the reason we don’t want to go, not the smoke, which isn’t true.

She’s making me feel terrible and like I have to choose between her and my husband. I know if I ask my husband to go, he will, but I don’t want to force him into that if he’s going to have a hard time breathing.

Please help. Am I being immature?