@BB-62 I suggest using "lose weight" instead of "with my diet", because "diet" strictly speaking refers to regulating one's calorie intake (which, while being something she does in other comics, is not applicable to this specific one), and ダイエット as a Japanese loanword can be used to refer to weight loss via any means, including exercise alone (which is what she's doing here).
For the final text box, you can replace "diet" with "weight reduction" instead of "weight loss", since it gets across the intentionality of her wanting to lose weight.