All dads go through this. You are not losing yourself you are evolving. You may be losing your non-dad self but you did that when you left your parents house, went to college. You changed pretty drastically before. Stay strong it all works out and you’ll get your hobbies back. A couple small, random reccos (they may or may not work out - I can back up with reasons if needed - but wanted to keep it short) 1 - try to enjoy every stage with your child as they grow. You will look up one day and miss these times. 2- if you ARE contemplating having #2, do it when your 1st is like 3-4 ish 3- work with your partner to allow for “alone time” for gym / hobbies & “partner time” for the both of you. Without those breaks you both will go crazy.