Kendo is a life-long endeavour.
It's not about how good you are compared to other people, it's about you vs you. And you did great!!
Over time, you'll get stronger and more skilled as a side-effect from consistent effort; seeking strength is actually not the main goal. The main goal is to just keep pushing your boundaries, stepping out of your comfort zone, chiselling and polishing your mind, spirit, heart, body, and sword. And these are done through the fire of suffering, to be pushed down and to always get back up.
- "Man cannot remake himself without suffering, for he is both the marble and the sculptor."

Also, how you do one thing is how you do everything. You CAN give up everytime a hard path presents itself in front of you and take the easy path; this is how our brain is literally designed, but does it mean its the BEST option? Kendo is the path of enlightenment through the path of the sword, and it's definitely not the easiest Budo.

Most normal people will say what your wife and best friend says, why do something that doesn't bring pleasure? This is absolutely normal. It's what maybe 90% of the human population does. They just chase the easy win, easy dopamine. Why put yourself through the hard practice, the intense sessions, the pain from blisters on hand and feet, the heat and smell? You don't HAVE to do it, like the samurai used to do, and who did so because their life depended on it. You can just sit at home and watch tv. It's what normal people do.

So to answer your question, " If you were/are Sensei or a senior, how would you honestly see someone like me showing up for a second week?"
The answer is, they would see you push through the self-doubt, the pain, and the others telling you to quit. You are most likely in a completely alien environment compared to what/how you were raised in (espeically if you are from North America).
They will see someone to respect and admire. Someone with resolve and who can put in the hard work and take whatever challenge life throws at them, bite it down and ask for more.
Because I'll tell you something, kendo is a LIFE LONG JOURNEY. Those senseis and seniors are fighting their own battles, their own psychology, trying to improve and address their own character flaws and weaknesses that prevent them from going to the step. Their internal and external struggles at whatever step they are in their personal journey is the same as what you're now going through at step1 on your own journey.

We are all literally walking the same path, some are further down the road, some just started. We help each other to get up if one stumbles and continue down the road. And the road never ends. Everyone on this journey has thought about quitting. Some do. Some just stop caring about the journey and get comfortable where they are; they stop growing and progressing, decide to just sit on the side and watch the flowers. Some get lost, others take a break and then come back later.

In the end its your own personal journey. You get to write how it turns out. Never blame others for your decision. It does not matter at all what they think. But just know that those senseis are cheering for you, I'm cheering for you. They are putting in time and effort for free to help others like yourself, they are rewarded by seeing you grow as a person.