Welcome to the blog, @Maudelicious - I think that many of us initially think we can do it 'on our own' .... and pretty quickly realise that it is as much a mental battle as a physical one, with surgery & followup active treatment.
You are coming up to your 1st year anniversary, so will no doubt be seeing your surgeon again, then your Rad Onc as well ...... it all brings back that initial 'shock' of diagnosis & the whirlwind of treatment that comes after that.
It is totally normal (almost expected) to fear recurrence & wonder 'what if' .... but if it is impacting your life, it is really important to seek professional help. BCNA has a help line that you can ring during work hours 1800500258 and they may be abe to help you with coping mechanisms or point you in the right direction, relative to where you live. Other links that may help on the site are here:
https://www.bcna.org.au/health-wellbeing/Many members see psychologists/psychiatrists as well - your GP will be able to help you with a referral. There is NO stigma attached to getting assistance to reduce the impact that Breast Cancer has on our lives.
If you add your 'city/town' to your profile information - others may be able to help with services in your area as well.
The Otis Foundation
https://www.otisfoundation.org.au/ offers free retreats to those with Breast Cancer once their active treatment has finished - the Virus has affected it somewhat, but well worth contacting them & seeing if there is a retreat available sometime soon for a special 'holiday treat' for you and your family and/or friends. Some of the retreats are in some of the most beautiful areas & is good for the soul.
I am lucky & have a couple of brilliant hobbies that keeps me pretty busy most of the time - so keeping 'busy' is a great way of driving negative thoughts from the mind. In normal situations, even volunteering at Nursing Homes, hospitals etc can be a very cathartic effect as well, helping those who are in even more need of help. Just now, tho, most volunteering actiities have been suspended for the foreseeable future, due to the virus.
Joining a new group - even online - be it craft, cooking, knitting - or checking out our own craft area can be a lot of fun too.
I hope that you are able to get a hold of these negative thoughts & boot them out the door - and start enjoying your life again xx
take care, and all the best xx