Am I standing in the way of happiness?

I’m so tired of trying! My husband and I have a 15 month old son. He works, I do not. His business requires him to be there late at night and sometimes he doesn’t come home until the wee hours of the morning. I put our son to bed and get him ready in the mornings. The last two weeks my husband has seen our son before bed twice except for one weekend. This weekend he will be gone most of Saturday night; Sunday night and possible all day both days. I hate not being with him. My therapist months ago advised a plan to get a babysitter and join him when he has late nights. He is in the event business and owns a venue so it would be appropriate for me to go. My therapist said it would get rid of our constant arguing over me not liking him being gone like this. My husband has to oversee the entire event but he can have a drink and socialize in between watching over everything so when I do join it’s loads of fun. I’m not anxious and we spend time together. We’ve done this in the past but only when the one person in the world I trust is available which is not always! My therapist wants me to train other people to watch my son but I don’t trust anyone else and the consequence is me still frustrated. This weekend we have a big engagement party at his venue and they want to see our son there. We know them well. It’s from 6pm - midnight. My husband wants us to stay the night at the venue but I don’t want to deal with the stress of him not sleeping because of the noise from the party. Maybe there’s a chance he will sleep but I can’t relax and am so anxious until that point and will be more anxious if he doesn’t sleep. Other option is me going and coming back home but all I see is work. I won’t have a minute to sit down while I chase him around a 12,000 square foot venue. My husband won’t help because he’s working. Our friends will hold him but he wants mommy all the time. I told my therapist just now I am so tired of going to these events with our son because it’s just work for me and she said “I think there’s frustration because you still haven’t tried doing events in the way we planned. (She means by getting a babysitter and me going to the event) We have talked so many times about how to make that more successful but you have decided not to follow through with it so I think it’s good to ask yourself why.” Something doesn’t feel right about this response. Am I standing in my own way of happiness here? It feels so hard for me to find a sitter to watch him overnight so I can attend these events and I’m too tired to go with my son because all I see is work when it’s so easy for us to stay home but then I miss my husband because he works so much. I don’t know how to see more of my husband without figuring out how to be at his work either alone or with the baby 😢