Dispatch/Outsourcing company in japan for chemical engineers.

This is my first time posting so i hope the format and context is appropriate. Wanted to share/rant in order to both share my experience and to seek out how others experiences varied, because i seldom find foreigners working in the same field.

I came to japan before corona hit as a Master\`s student in Life sciences (Biotechnology), and as soon as i graduated i was offered a job in a dispatching/employment company (派遣会社). I naively accepted because i thought i could experience alot of things. Surprise surprise, the work was chaotic. They could send you to extremly high level places like the national institute for infectious diseases or to work as a line worker in a factory, of which i have experienced both. The salary is horrible (2.9M at best and 2M at worst annually). You still get paid during downtimes such as standby periods between work, but you get expempted from bonuses and supplementary salary (Technical support etc.) there have been months where i had to live off of 100,000 purely because the sales agents could not find me work and there were holidays within the month, which you ofcourse do not get paid for.I have been looking for a different job but with this chaotic history and niche field, i have no idea what my options are.

For reference, my JPTL is N2 and have a diverse life sciences background (Molecular, genetics, botanical, etc.)

So, i wanted to share this to see if anyone can relate or has been in the same situation. Advice is appreciated but just any insight into the this mess im in would be helpful.

PS; My salary is at an abyssmal base of 175,000 before taxes and supplementary additions, no offence to those who are but my friends who work as kindergarten teachers make double that.