Howdy, OP.
Although you might be missing out on training or knowledge that other first-year teachers are getting through more officially organized programs, you still have a good deal of knowledge about what is and what isn't going well in your class. Don't sell yourself short!
As you advocate for other supports, don't forget to just go to your mentor and say, "Hey, I'm having trouble with x. What do you recommend?"
You might also see if your admin can give you or your mentor a sub day so that you or they can observe the other. You can either pick up some great new ideas or your mentor can target some things you might not have noticed in your day-to-day teaching.
Hang in there!
