My meditation background is a few years of inconsistent meditation from various sources with a growing interest in Dharma over that period. This was followed by some meditation under the TMI system, consistently, for a period of a few months.

At a certain session in TMI, though I would classify myself as stage 3-4 on most occasions, my focus on the breathe became almost entirely effortless. From this arose some distortion of bodily perception (feeling like my posture was crooked when in fact it was quite fine), followed by intense pleasurable energy starting from the pelvic region and upwards towards the head making it feel very lightweight, like when one hyperventilates (though I am almost certain my breathe was very shallow at the time). This energy died down and was followed by what I imagine equanimity must feel like, a state of intense calm wherein the moment felt entirely blissfull and perfect. 

After some time I got up from the cushion and went to get groceries and had a sense that all sensations (including thoughts and actions) like bird song, cars driving, things occuring where coming from the same "space" and everything was unfolding on its own. Felt weird but quite agreeable. This only lasted a few hours to days (memory fails me), but was followed by a general contentment, empathy towards others, and less "stickiness" to sensations (less rumination). I still had unpleasant thoughts or feelings and it's not like everything was fixed but I felt a lot better about where I was in life.

I since then moved out to a new environment which unfortunately lead to ending my practice for a few months (loss of motivation, intent) and in the midst of being stuck here in pandemic conditions I've been dealing with some more depression and anxiety symptoms, as well as the sense that nothing satisfies as much as meditation (at least as meditation once did), though I am yet to translate this unsatisfaction with everything into dilligent practice, I am more or less doing TMI everyday again for a couple past weeks.

The primary reason for my asking is I'm trying to work out to what degree am I dealing with the Dark Night, and to what it's simply environmental factors so that I can act accordingly. I'm also asking because the Dark Night seems bloody awful as some describe it, and if that's what I'm going through then that actually gives me some comfort as it's not that awful as of yet, but maybe that's because I've had brief experiences of depression too, and this is awfully similar. So I'm torn between continuing to practice to escape the Dark Night, and wanting to quit/ relax my practice as I'm not sure I'm in the best possible position to deal with something that's much worse than this, and to this end I feel afriad of large amounts of sitting time.

Thank you for reading this, and I am willing to provide elaboration so that the diagnosis may be better.

To add to this, my greatest fear is that my arising and passing event is merely jhanic experience and I'm using conformation bias to construe depression as a dark night, which would lead me to practice harder and end up in the real dark night and make life a lot harder. I'm in the midst of university studies so it's imperative that I'm well enough at least to do well in that, and to have fun in uni as those days only last so long lmao. Thanks.

Diagnosis is never a sure thing, but to me that experience sounds like an A&P. A&P and 2nd jhana can be quite similar on cushion, but jhana on it's own is unlikely to produce that sort of effect off-cushion.

The Dukkha Nanas aka Dark Night are simply an experience. I would ignore the hyperbole people throw around about them. If you go on retreat or meditate 3+ hours a day they can indeed be intense. I would generally recommend getting through them by meditating more if life allows it, but you can always back off on practice if things are too intense. Chances are things will be no worse than they already are now.

Given what you describe I really think you have nothing to lose and everything to gain by practicing consitently - an hour a day if great if you can manage. I would consider tweaking your practice though. TMI is a great method, but it can be suboptimal for navigating the Dukkha Nanas, especially if you hit them in an early stages of TMI.

A lot of TMIers don't pay enough attention to the entirety of their experience to successfully navigate the DN and the TMI stages cause a lot of craving/aversion. This can be self-defeating in the DN because your ability to concentrate is almost certainly worse unless you happen to be in A&P / EQ. In fact, both TMI teachers I worked with recommended other practices after A&P.

I would strongly recommend adding a noting practice (described in MCTB, but do not go manic - noting once or twice per breath is way more sustainable) and maybe choiceless awareness (choiceless attention in TMI parlance) or "do nothing" as described by Shinzen Young. You can start your sit with 1/3-1/2 shamatha if you like, but then switch. These type of practices are much more open to whatever comes up, which is key to navigating the DN. It's literally like a finger trap - the more you struggle the longer it lasts / harder it becomes.

The noting practice suggested above is very helpful if things get unpleasant. It's much easier to get some distance from these experiences if you label them, whether on the cushion or gently throughout your day as circumstances allow.

For some more info on this territory I'd recommend browsing the relevant section in this collection of posts, as that advice helped me a lot when navigating similar territory.

https://shargrolpostscompilation.blogspot.com/