Don't worry, your situation sounds ideal: safe environment check - starting with reserved dosage rather than hubrous, check!
The duration is in my opinion a trick... how much and how long it messes you up is much more important in my experience - I shit my pants for DMT which lasts about 5 minutes and don't get me started about Salvia, I find mushrooms a bit scary because of sometimes feeling like I lose my mind on it, but with LSD usually I feel mostly fine unless I eat a TON of it. Sure, sometimes it's pretty wild but somehow to me it feels reasonable. Then again, I am a reason sort of guy.
You would be right to be scared of a trip-gone-wrong with a long lasting psychedelic (for me that would be the 24+ hours kind), THEN the concern is so very warranted... but it's not a
linear sort of thing. It's more complex.
Just make sure you're not too hung up in one place... move around, explore, have faith that moving from one weird crazy thing to the next will ultimately be benign... it's like a journey but you WILL come home. Your sense might tell you that if you get an "accident" during that journey you won't be able to go anywhere ever again... but actually fear itself is more something to fear / avoid than anything else.
Sometimes I have heavy trips and I fall into one of those traps: I panic or despair, I think: boy I really dun did it this time...
8( but what saves me then is realizations of positive thinking... examples:
"Putting trust in yourself means you receive trust from yourself" [you can't go wrong there].... or:
"Make the best of it"
Maybe with mushrooms type psychedelics this is less important because there is a lot of unconscious stuff and feelings at the wheel - you have less control, but you will also come around. I guess with acid it's a bit more lucid and your own responsibility, but generally that is a huge advantage.
For the most part - LSD type substances make me feel deeply amazing in a relatively stable sort of way.
enjoy