Welcome! You have come to a fantastic place for support and motivation (but you already know that).
I think you have already made steps in the right direction by realizing that something needs to change. By simply making this post you have already begun to take action which is important.
As for where to start, you should keep it simple at first. Set small goals that are measurable and achievable. For example, eat 1700 calories everyday this week. Or workout 3 times this week.
Build up some momentum. Start chipping away at that 100 pound goal. You can do it! I look forward to seeing you achieve that goal in the near future
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