Yes, I feel the way you do, and yes, I understand your complaints and your frustration.
HOWEVER:
I have been poling for 6ish years (maybe 7, I can't remember?) and I haven't mastered the basic invert. I've been poling that long and still struggle with a thigh rest. I have been poling that long and have little muscle from pole, little change, and a whole lot of crushing self-defeat.
And, that's the truth of it. I defeat myself, I put myself down, I don't celebrate ANY victory. Ever. I don't trust my body and I don't try new things very much. I am often "On hiatus" these days.
I know these things are MY fault because I have been running for a year and a half. I started to see changes, after about 3-4 months. Changes in my knees, changes in how my legs move, changes in my stamina and ability. But, it was very consistent, slow, aggravating work. And I just kept at it.
Most people, after a year and a half, would be running well past 10k by now. Most can get to a half marathon (24ish miles), if not a full marathon.
I am only running 4 kilometres, working on 5. In a year and a half.
But I'm proud of my progress, and it taught me something. No matter how hard the work or how horrible you feel, you'll always feel better after you do it. No matter how much you think you suck, you're always working forward. Consistency is the only thing that will bring you results, and it's the only thing that will really make you feel good about what you're doing.
You will only get good at that Fireman spin after you've done it so many times you don't even have to think about it anymore.
As for your other complaint, of weight:
When I reached adulthood, my normal weight was around 160lbs. That is where I stayed for years. That was my non-training, relatively sedentary lifestyle weight.
Now, with running, I am 200lbs.
I am 200 pounds because I traded in my body fat for a bunch of muscle. My calves are half again (at least) the size they used to be, and are powerhouses. My thighs are showing more muscle, and a bit less fat. My core is tougher, stronger.
I am NOT 200lbs because I'm fat. Or because I'm doing something wrong. Or because I eat wrong. Or whatever other thing people want to tell me. I am not unhealthy at 200lbs.
In fact, I am the healthiest I have ever been in my life, and I expect that to continue for a long time.
If I see more than 200lbs I'll know it's because I need that weight- and that muscle- to get my goals. I need it to make sure I can do the basic invert, and maybe even an Iron X one day.
There's this stupid idea somewhere in society that if you are "fit," you weigh less. It's not true at all. Your weight on the scale and what you look like are completely removed from each other (well, perhaps not completely, but in a much larger way than most people think), and your weight has nothing to do with your health.
It sounds to me like you're putting a lot of pressure on yourself to progress, to be something specific, to see certain changes that may be unrealistic.
It also sounds like you're comparing yourself to other people, and you're finding yourself "coming up short" by your own standard.
Do not compare your blooper reels, or your life, to someone else's highlights. Don't ever think that the images on Instagram are anything but the best of what people want to show.
Whatever you think an artist does their art like is actually only 10% of what they do. The other 90% is the sketchbook, the messed up sentences over and over, the dropped stories that fizzled out and went nowhere, the pages and pages of drawn ears, the hours and hours and HOURS of doing one move over and over till they just can't fathom not doing that move every single time they come to dance.
What you're seeing is the culmination, the top of mount Everest. You didn't get to see them climb every single stupid other mountain to get to Everest, or even the climb of Everest itself.
Your journey, in essence, is incomparable to anything else you see. Your journey is yours alone, and comparing it to someone else's yardstick, someone else's successes, is selling yourself short. It's doing you a disservice.
You're awesome, and you've gotta keep being awesome on that pole until one day you tell someone "Oh, Look what I can do!" And show them how awesome you are.