I'm touched by your ability to express your emotional connections to the natural world and your thoughtfulness in considering the impacts of your actions so carefully. I am also a deeply sensitive person when it comes to things that matter to me, and I've had similar thoughts as those you expressed here.
Regarding the need to consider, thank, respect, honor, express gratitude and so forth with each individual being that your actions impact: I have found that for myself, focusing on three specific things has helped me navigate these waters with less emotional confusion.
First, I try to maintain a state of open awareness. This allows me to connect with the beauty, purity, and perfection in nature, as well as to learn about patterns and connections and relationships within and without. It's almost like seeing with the "child's" eyes / mind / heart - full of wonder. Very energizing and empowering.
Second, I try to maintain a state of appreciation. This is easy with the spectacular or rare things we encounter, but can be more of a challenge with things that seem more mundane or common to us. By appreciation I mean trying to see the values of those things, whether that be to me personally, to the ecosystem, to the earth, and so forth.
Third is gratitude and its' expression. Although I do at times feel moved to express my gratitude individually, sometimes I conceptualize it in a larger sense (gratitude for the forest, the sky, the water) and most commonly I express my gratitude in an even larger sense to my "pagan" concept of Earth Mother and the Universe.
I am a non-theist who does not believe in the concept of a supernatural deity, however I have found that establishing the practice of saying blessings for the things that enter my awareness and that matter to me has been extremely helpful. Saying a little blessing in my own way, whether it be one of concern or gratitude, eases my emotional concern / distress greatly and keeps me aligned with my strength. It helps me remember to think larger than myself - to remember that I am doing the best that I can, as a flawed human being trying to find her way in a crazy-mad world, at that moment in time, AND that I'm not the center of the universe
All we can ever do is our best in the current moment, and our best changes from one moment to another. It is grounding and centering for me when I remember this concept, and I practice the same thing whether I'm expressing gratitude for a meaningful wildlife sighting or expressing my concern over a neglected chained up dog I see in my neighbor's yard. It helps me to release my emotions "to the universe" if you will. (I hope that doesn't sound too flaky - don't mean to alienate you with my personal ways of relating)
One final thought, I have also found that using a "compartmentalizing" strategy with emotions is a useful tool at times when I feel like it's all just too much. The idea is that you put each concern in a safe place - a "container", acknowledge it's validity and importance even if it's UGLY, put the lid on it, and save it for a time when you are ready to address it. This strategy requires that we agree with our self and our concern that we will revisit it, but at the right time, and not all jumbled up into a big giant ball of shit with other feelings and concerns. Breaking it down into smaller pieces is my number one strategy when i feel overwhelmed by anything. Like unraveling individual threads from a tapestry and interacting with them one at a time...
I truly believe that it is not "if" we can deal with the emotions, it is "when", and "when" is whenever we are ready. The process of envisioning their storage in a container can actually help us physically, since the "mind" is inseparable from the "body", it can help us store those things in an appropriate vessel so to speak, instead of them causing us inescapable pain (literal and figurative pain).
Hope I haven't blabbed on too much here - Best wishes!