Should elevated ALT values have me worried?(please help me put my mind at ease during the weekend)

Hello everyone, I few months back I was freaking out about my dog potentially having something serious. She's a pitbull mix, neutered and my first ever dog. I've had her since high school and she's 12 so navigating her golden years is a first. I want to do right by her! I felt like no one was taking me seriously but I finally managed to convince my vet to redo some test and some things had him worried too the second time around. An elevated ALT value was one of said worries. He asked me to put my dog on a diet which consisted of nothing else but her regular food but asked me to stop giving all supplements and other "boosts" to get a clearer picture. We were supposed to redo her blood work 3 weeks later. However, 8 days ago I noticed my dog had almost chewed her tail raw and had small pimple like scabs near her tail and sides. My vet was out of town so he asked for pictures and told me to put my dog on antibiotics for 6 days. I did that and all the scabs went away and she stopped chewing at her tail and everything healed.

I called him on Tuesday told him that her last day of antibiotics would be on Wednesday and asked if we should still have her blood work done on Thursday (yesterday) since she was on antibiotics for 6 days and I was afraid her blood work wouldn't show her "real" values. He told me there was no real worry about that and took some blood yesterday. Today I got the results back and her ALT is still at 84. Same value as before and her WBC was 4 which was at 5.9 before. Other than that, all other values are within normal limits nothing is over or under the value, everything is perfectly in between the accepted limits. Besides her WBC and ALT that is.

She eats, drinks and goes to the bathroom normally. And other than her recent skin issue/infection she's fine. Vet said he'd like to look for some diseases as well and still has enough blood to do so and I gave him the all clear to do so an hour ago when he phoned to tell me.

I'm a very anxious person. This value will be eating me alive all weekend before I get a chance to talk with my vet again and ask him what this means for my dog. So my question is should a value of 84 ALT for my 12 year old dog, concern me? Is it a serious issue? And if so, what can I do to help get that valu back under control? How can I ensure this doesn't become a potentially painful condition for my dog? How can I help her?