There of course will be many things to test you in life. There may well come a time when you cannot physically and mentally handle any more, beyond not wanting to. Your body will and mind will give in.
Anxiety is the dreadful start of your body telling you that you are taking too much stress on.
Choose your battles. Avoid what you can. Remember you need your own strength to then be able to help others. You cannot forget this. You are therefore no less important.
Protect your strength. If you carry too much. Walk away. Heal. Make sure you have healed.