Oftentimes, the damage caused by over watering cannot be 'fixed' by drying the soil out. Planting into a VERY coarse, rapid draining potting mix can go a long ways in preventing problems in the first place, even for those who tend to be chronic over-waterers. LOTS of us are guilty of this at some point, lol! Using a great deal of perlite, bark fines, and/or Turface (for example) insure that you'll have plenty of large pore spaces in your potting mix to promote the essential water drainage and a constant oxygen supply required for healthy root growth within a container. Please know, too, that moisture meters are notoriously inaccurate.

Here's what I've done with a meyer lemon plant before. But I would wait to hear someone else say this is a good idea before you should try this, maybe I got lucky. I thought mine was about dead and I just figured what do I have to lose. I got rid of all the old soil. Pruned the roots lightly. Cut off about 2 inches off the end of each growing point then put it in some fresh soil and just wet it enough to allow the soil to set up. I kept it out of light for 2 weeks then I set it out in light. After about a month I saw some new growth. Once I saw new growth I fertilized and let it grow. It's doing good now and hopefully next season I'll get some good fruiting. Last year I only had one lemon but it was large and tasted good as fresh lemonade. I have a little one on it now but I don't know it's chances since it's in the garage at nights and days that don't warm up past 50. So the lemon hasn't grown much this past month, it's about the size of an egg now.

Wow you have run the full cycle with your plant. I don't have much advice other than check for more bugs and give it some time to adjust perhaps. I have a Chinese mandarin that I started from seed and I bring it inside in early fall before night temps get below 15 degrees or so. It lost quite a few leaves after bringing it inside this fall. I use mostly peat and about a quarter of garden soil, that has been working well. No bugs so far. I have been using rose fertilizer that has micro nutrients and flush every second time. I haven't used grow lights yet but will have to if I want fruit. best of luck with your plant.

I have read also to allow the tree to do its flowering cycle because it has something to do with hormones. If you remove the flowers, the tree will just continue to push them out. If you don't want fruit, wait until the cycle has passed and then remove the fruit. Last year my tree pushed out blossoms, set fruit and then I ended up unknowingly knocked most of them off while moving it through my sunroom door. The plant focused on foliage the rest of the year.