29 [M4A] PA/online Are you a personal trainer?

I have been feeling a bit uneasy with some aspects of my personal training experience, but maybe l'm overthinking it. My trainer is very hands on, which is fine to an extent, but sometimes it’s more than what I'm used to. He makes a lot of physical adjustments to my form, and it's starting to make me feel uncomfortable. I'm not sure if that's normal or if I should speak up about it. When he is spotting me it can be too much, and he gets too close.

He's also been insisting I wear very specific tiny underwear and short shorts because he says they give me the most freedom and support. I'm not comfortable with these requests. The underwear is very small and revealing, and so are the shorts. The shakes he gives me, that he personally makes, have a really odd taste. He swears they are very helpful and a must for my regimen. I'm starting to wonder if I'm just overthinking it or if there are red flags here. I'm not sure whether I should address these concerns directly with him or if I should look for another trainer who might make me feel more at ease. 

Are you a personal trainer or have experience with one and be able to talk to me about this. Can I pick your brain? I'm just trying to figure out what to do. Am I just overreacting or does this sound pretty normal? My girlfriend thinks I'm overreacting and should give them more time to see. What do you think? Should I give it more time to see, or if there’s no evidence of odd behavior to move on? I would love to talk to someone about this, and get some perspective.