Being a lead vs actually leading
So being a team lead is not the same as actually leading. Being designated the role of team lead does not make you automatically lead the team. You have to be responsible for decisions, know what your teammates are doing, what the codebase is doing, what the customer wants, what tech is out there and what is being used currently. Have a grasp on team morale and making sure it is kept high. Guard your teammates from outside attacks from project managers and/or clients.
It takes quite considerable amount of time and energy to keep the quality of the codebase up to par as well. You have to actively take steps to do all of this. So people that are more passive in general have to do some more steps to make sure all of these processes are being executed and followed. Also take more steps to make sure all team members are engaged.
It can become quite taxing on introverts as well, as there is so much interaction going on. Not to mention the fact you also want to maybe still evolve your developing skills, for which there seems to be no room anymore. The key is balance and repetition. The more you do it, the less effort it will take. Movement is more important than quality sometimes.
Also be able to lean on your team members but not as a crutch, be confident they will get the job done and done correctly. Make sure to be able to state the positive as well.
Just take it small steps at a time and your team will be great in no time.