If you want to have kids, being a little unhappy for a short while is a very small price to pay... assuming it even happens to you. Can you imagine how women feel about our petty male complaints? I mean... come on man.
Also, and I hate to say it this way but I want to make sure I it has an impact:
You are no where near ready to raise a child if going off TRT is making you nervious.
You need to really think about what it takes to be a dad and let it sink in. The sides of low testosterone are the least of your worries. Being a dad is a sacrifice of time and an exercise of your mental health with constant ups and downs.
In other words, raising a child is a totally different level of exhaustion and its constant for at least 19 years! Its 100% worth it, I have 3 myself, but you need to know what you are getting into and honestly, this is good practice. You need to learn how to handle non-stop mental stress.
Last, and this is in appreciation to all the mothers out there, we, as men, have it easy. So just do what the doctor says. Its not a big deal. You will see what I mean in due time. Be kind to your woman. She is the one who is doing most of the sacrifice.
All that said, your mental state is important. My recommendation is go and enjoy other things in life. Many men get fat when they start having kids. Believe it or not, the path of getting fat is actually fun. I mean who doesnt want to eat babyback ribs, a giant carb load of mac'n'cheese and chocolate cheese cake every day? You only live once, go enjoy it for 6 months. If food isnt your thing, find something else to take you happy. Maybe its video games? How about making more money somehow? Learn the guitar? Travel (it will get harder once kid is around)? Start a vegetable garden? You will need to learn how to cope with the kids nonsense anyway so this is good practice. I know its hard to believe, but there is more to life than our balls... (let the jokes commense)....