Congrats to you, and welcome!
I am in the opposite boat, two years ago I gained 20 lbs in just a month, for still unexplained reasons. I've long been prediabetic, diabetes runs very strongly in my family, and my blood sugar and cholesterol went completey crazy at the same time.
My doctor gave me a stern lecture and implored me to lose weight, or eventually go on meds. So I started eating right, quit smoking, and started exercising. It took one entire year but I did lose the weight, plus a little bit extra, landing at what my doc considers my "ideal" - not too thin and not overweight. And all my numbers are back in normal range again.
Like you, I had to completely purge my closet and rebuild. I found it helped to first take a good long look at my lifestyle. That's where I started. My lifestyle had changed drastically - I had to face facts I am a telecommuter now and don't really need a closet full of career wear. I needed jeans instead!
Next, I looked at items that I loved, and asked myself why I loved them - other than "making me look skinny." For example, certain items from my old wardrobe are coveted because the color suits me. Other items were coveted because they are classic and timeless. Still others, because they were just quirky or unique enough. Some, because of the fabric felt good on my skin. And others because they were versatile!
These - combined with a lifestyle assessment - are good clues about where to start.
Lastly, I found it really helpful to cultivate a positive attitude and work on ridding myself of negative thinking. For years, I've hated my body whether it was thin or fat, fit or healthy. It was never quite right. Well, I'm in my 40s now, and not only do I understand that weight is about health much more than how one looks in clothes, I'm also realizing this is the only body I've got, so I better just embrace it and learn to love it!!
So you may read me correcting myself ... flat butt is a "tiny" butt... I'm an "hourglass" not an "apple"... etc. I'm still working on it.
Be good and kind to yourself. That's the most important thing.