Interesting story, according to you, the purpose of this investment is long term, however, I'm wondering how you considered Bitcoin as your best investment? Don't get me wrong, but, the amounts being invested are quite small, considering Bitcoin's value. I believe that sometimes, investing in some other reputable altcoin, such as Ethereum, Cardano, Binance and many more, is deemed more profitable than purchasing Bitcoin.
First of all, this thread is about bitcoin and not about various shitcoins, and surely if you are going to consider any investment you need to consider both upside and downside potential, and if you are investing blindly with a kind of DCA strategy then you are betting that in the long term the price is going to be higher than over the period that you had been buying into the coin. Accounting for the fundamentals of those various shitcoins that you list need to employ some different calculations in terms of figuring out the various downside risks that each of them present.. including that each of those smoke and mirror shitcoin projects have way greater chances of going to zero than bitcoin and each of them is dependent on bitcoin's performance to have any value at all, even if they might have greater short term pumpamentals as compared iwth bitcoin, but we are not talking about short term here either... especially when talking about DCA, and even OP has mentioned that he has at least several years that he is considering keeping on injecting value into bitcoin.
In regards to the amount invested, of course OP had listed out his own personal budget, including how much that he believes that he has available to spare to put into bitcoin. Historically relatively small amounts have paid off quite well, but surely we cannot expect future performance to necessarily be even close to as high as historical performance has been.
I think that in the end, people do what they can, and they should enter into bitcoin with at least a 4 year investment horizon and if they can consider their investment to be more than 4 years and maybe more than 10 years, then surely over that time they might improve their cashflow and be able to invest more into bitcoin if they are able to improve their cashflow or cut their expenses more. There might even be some times in which windfall amounts of money might come available that can be injected into the BTC investment to add to the stash.. and surely if any of us is investing in the long term, then if we are continuing to invest into bitcoin along the way, we can assess our value and how long that we are ready, willing and able to let the investment to continue to ride.. Of course, if there develop desires to cash out some or all of the investment, then there would be considerations about whether that value is going to be used for other investments or for consumption.. and if the person is giving up the idea of investments or just considering that the investment has run its full course.