First, congrats - great job losing weight, as I'm sure it wasn't easy.
A lot of good advice above - especially, waiting until you're secure you've settled into your new weight.
My only small add is to consider that alterations can be quite expensive - especially because, I'm guessing, you'll need some pretty extensive ones and, usually, extensive alterations are rarely perfect, i.e., you might like, but probably won't love, the results.
Hence, once you are at your "permanent" weight, I'd take a hard look at what you have in your wardrobe, how much of that you really want, how much of that can be truly altered to a very good result and how much all of that will cost. Then, compare that to buying a new - proabably, smaller - wardrobe to start.
You also, as noted in above posts, might want to do some combination to "bridge the gap." Hence, alter a few things to keep you going and add new over time.