I felt compelled to reply to your message to try and provide some ease and pressure off of you having worked for City law firms a long time. It is easy to read that everyone is leaving law (but from the law firm I work for, they are leaving as they got jobs to go to at other law firms, not leave the industry entirely). Very few I know have left it entirely but I guess there are some that do. Other industries are also undergoing staff losses due to the great resignation at the moment. So I guess it is about putting it into perspective that it is not just law that it is happening to.
There is a lot of emphasis put out there that working in law firms will require long hours but it is not like that all of the time. Associates tell me they may work long hours one evening but not the next. You can also put your requests into HR where you would like to work so it doesn't have to be in practice areas where you feel the hours will be long. May be a secondment will be a good seat - I have heard trainees tell me that the hours are better at banks - I can't say for other sectors. It may also be a good idea to find out what your firm's well being services they have available. Having a mentor will also be valuable to you for someone to go to talk to so you don't feel alone and you can air anything you feel you are not coping with. Lots of firms have mentors in place as it allows trainees to settle into the teams better. If there is no mentor, I am sure you will have other trainees you will click with and you can lean on each other during your trainee journey. Most of all, try and look forward to it, it is a journey. I remember a trainee who came to our team as her first seat and she did look petrified but after a few weeks she seemed she had settled in fine and was getting into the work. Take your time, prioritising tasks will be a good idea so you don't feel overwhelmed. Lauren who just spoke for TCLA said you can always approach an associate in a team and saying you are unable to fulfil everything being given to you at the moment and associate will help you in working it out. Its all about working as a team in each of your seats - talking to other team members, etc on your work and don't be afraid to ask questions, there is never a silly question on something you have not done before. Good Luck!