new here. 185 lbs lost. unsure where to go next...

Hi everyone. I finally decided to join this community. I figured talking with other might help get me a little perspective on my current situation.

In the past 3 years, I have lost 185 lbs. This was 80% diet, and 20% exercise. I didn't even start exercising until I had lost about 150 lbs. I was too embarrassed to step foot into a gym before that point. Now i walk an hour on the treadmill for an hour a day. I don't wear a body bug, or fit bit or anything like that, and I KNOW the treadmill calorie counters are not accurate...however, according to that, i burn about 450-500 calories each workout. I walk at a moderate pace. I am now starting to look into strength/resistance training to build up a little muscle.

SO...that's the good...here's the bad and where i can use honest opinions/advice

Full disclosure, I have not eaten more than 1,100 calories in the past 3 years. Yes, i know now how unhealthy that is, but at the time, I had no idea. I started out eating 1,000 calories a day and stayed at that for quite a while (maybe a year) with the occasional binge here and there for a birthday or holiday (i am not perfect) then i hit a plateau and went down another hundred calories a day, stayed there for a while, and so on. I was recently at 800 for quite a while, until I hit another plateau and honestly, for the first time, became exhausted. Not just mentally, but physically. I stopped and thought about how I felt, and started to do some research and have come across quite a bit of literature about metabolic damage. I do think, without a doubt, i have slowed down my metabolism. I would love nothing more than to start (slowly) eating a bit more in hopes of getting it back on track and being able to eat more, because honestly, I don't want to starve anymore. I am tired of it. I am tired physically. Literally exhausted most days. Am always freezing. Haven't had a menstrual period in almost a year, and many other horrifying side effects that I wish I would have taken seriously sooner.

My question is....has anyone else gone through this? What was your experience? How do you think I should start incorporating calories back into my diet? Right now I am adding 100 more calories a day per week. For example last week, I was at 800, this week i am eating 900 a day. As far as exercise, i've been told by the trainer at my gym it's too much, and i should cut back on my walks to 3 days a week. Does this sound right to anyone else? Do you think the resistance/strength training will help?

I KNOW I did this the unhealthy way, but please know, it was never my intention. I never meant to or wanted to starve myself. I didn't know what I was doing. I was not 330 lbs because I knew a lot about proper nutrition to begin with, so when I decided to lose weight, I just did what sounded right. I don't regret it, because even though I did this the wrong way, I am VERY happy to not be obese anymore. I just want some advice as to where to go next and to reach my final weight loss goal of exactly 200 lbs. I want to do it the healthy way, and just overall be a healthier person. Any help and or advice would be much appreciated.