A few things.
1. You're not doing anything wrong.
2. Focus of true goals, not hoped-for outcomes. A goal has to be something you can control, and there needs to be minimum and maximum standards in order do enough work to grow, but not burn out.
For instance "I want 100 subscribers by April." This is not a goal. It is a hoped-for outcome. You have zero control over that. It might happen, it might not.
A true Goal would be, "I want to produce two or three videos per week," or, "I want to amass 100 to 150 videos this calendar year." Those are goals. You have total control over that. What will the outcome be? No one knows. That's why Google/YouTube gives us analytics.
3. As a fishing channel the most difficult thing is getting out there on the water. Let alone catching fish! The reality is that fish only bite two week out of every month. Why? The new moon and the full moon. It isn't realistic for a fishing channel to get out quality fishing content three times a week. I would recommend that you target the week of the new moon and full moon to get all your fishing footage for the month.
4. Climate and seasonal patterns. As fishermen we have to contend with the fact that fish don't care about our YouTube schedule. Warm water fish don't care to bite in cold weather. Cold water fish don't care to bite in hot weather. When the river floods it's too dangerous to fish. Drought years put extreme stress on the fish, making them not bite as much.
5. Even with the right time of year, during the correct moon phase, the weather often gets ion the way. here we've had continual tornado warnings mating it very dangerous to fish with any regularity.
6. So, with all these difficulties as a fishing channel how to we get out content? There are three approaches I believe.
Approach #1 High Production Value, Low Quantity
1. Only produce high-end, Nat Geo-like content. This is my goal. I want every fishing trip to be like a Jacques Cousteau documentary film. With this approach even a 10 minute fishing film would easily take a month to produce.
2. The limitation here is time and expense. I don't have the cash to buy to or three Cannon 300 cine cameras. However, all of today's cameras are phenomenal. My pair of Z-cam E2C cinema cameras are better than a Canon C100, Canon's entry level cinema camera. Paired with vintage Canon FD glass, this has produce the same look of many 1970s documentary films that I like. I hate an image that is too sharp and too perfect, but that's personal preference.
3. Also waiting for the perfect time to fish almost never works. It's better t get out there and get some footage even if it doesn't produce the best fishing action. It's about the story anyway.
Approach #2 Low Production Value, High Quantity
1. Honestly all of us produce content at a much lower production value that what you see on T.V. or even on PBS. Here you concentrate on reviews and tutorials. You're producing a lot of content.
2. Sit down, make a list of every piece of gear that you own, e.e.g, line, rod, reel, hooks, fly-tying materials, fly-tying tools, waders, canoe, kayak, everything you use to fish. Each one of those now becomes a review video or tutorial. You whole channel could be reviewing tools, and gear. In fact that is a great way to get lots of subscriber quickly.
Approach #3 Mix the Approaches From Above
1. For me since I have the desire to teach and a taste for the arts. I mix the above approaches. I can only get out one or two high quality fishing adventures per month, but I can create tutorials, online classes and review many times per week.
2. This will take some time and planning to get used to. It can take some time to get to that point, but it's worth it.
In the end it isn't about the number of subscriber you get. It's about the number of people you help, serve or entertain.