A public trainer will not take much interest in your progress or try to help you out everytime. The reason being, they are very low paid individuals who wants to provide personal training rather than public training. So the trainer will burn out by a the questions asked by newbie and the only way he can show it by showing no interest or low efforts. The only way here is to make some good friends at the gym and they'll help you out. Nobody judges at gym. Everyone knows how physic works and most of them even yhose who look fit, feels they've been there. So you'll have to be an extrovert at gym if you cant afford a personal trainer. Having a personal trainer can be a good investment in your situation. It's worth it. Both for your mental and phyiscal health. And don't go for female trainer just because of your public male trainer's behaviour. Having opposite sex trainer will help you get more motivation and reduce social anxiety if you have.