My dachshund is scared of other dogs on a walk, looking for advice

Hello hello!

I've had my beautiful girl for just about 6 months now, she's a year and a half , mini long haired doxie.

She's wonderful and very intelligent, mastered all other parts of training, and is great on a walk alone or with other humans near, but every time we come across another dog, even at quite a long distance, she freezes up and just stares at the other dog until he's out of sight or has passed us. She's absolutely fine at the dog parc, on walks without leash at the beach

I've been reading about possible leash reactivity, techniques that include changing directions, treats to her nose, the "look at me!", I even have some real good treats in my pocket for when she doesn't react/ is okay walking past, and some rare days she will be just fine, the next it feels like we're back to day 1.. and on those days, none of these techniques work sadly

I'm planning on a visit to the vet and maybe considering going to a professional to help, I'm scared I might not be doing things right and making it worse for her, and was wondering if any nice souls would have some good advice on this thread? I'm at a loss and genuinely want to make things easier for the both of us, she doesn't deserve to be scared on a walk 🙁

Thanks so much for taking the time to read this, take care out there wherever you are! <3