I recently started using listerine advance defence gum treatment mouthwash and found that even after a couple of days my mouth felt cleaner and gums less swollen. Admittedly I struggle using it every day because it tastes minging but it might be even more helpful for someone with more discipline!
I understand so much where you are but from a different place. I avoided dentists for two decades because of a phobia. I finally plucked up the courage to ring a helpline and it changed my life. They talked me through everything, allayed my fears and got me to a place where I could face up to it. Luckily, Mrs SRE‘s dentist was happy to take me on and has been amazing. On mouthwash though, the advice I’ve always had from both the dentist and hygienist is that you really shouldn’t use it after brushing, as it washes away the toothpaste, which is there to do a job. All I can say is stick at it because it can only get better. 
ETA on topic: I love how great this place is and how the canal are, even though Guset is last year’s snow