DEAR ABBY: I just finished reading the letter from "Happy at Last in Oklahoma," the 85-year-old woman who changed her eating and health habits at age 80. What an inspiring letter!

I am 31 and happily married to a wonderful guy. We have a preschool-age son. Like "Happy in Oklahoma," I have also doubled my weight and am very uncomfortable with my shape.After reading that letter, I am encouraged to try harder. My moods dictated my eating habits. Whenever I felt bored, lonely, sad or unhappy, I'd eat. Every Monday, I would begin a new diet, then I'd fall off it and try again. Abby, that lady's inspiring letter has changed my life forever. No more starving myself, overexercising and beginning again for me. I will begin right now to change my bad habits.

I cut her letter out of my newspaper and plan to keep it handy for reinforcement when I'm tempted to "cheat." May God bless this wonderful Oklahoma lady. Thank you, Abby, for running her letter. - CHANGING FOR GOOD AT 31

DEAR CHANGING: Many other readers were inspired by that letter. And for those who missed it, here are the highlights:

"My advice to people who want to do what I did: Remember, you didn't get fat overnight. Ease into your new habits. Never talk about what you are doing, just do it! Let others discover that you are losing weight.

"First, cut down the size of your servings, then limit your meals to healthy foods such as fruits, vegetables, cereals, lean meat and non-fat milk. Drink at least 10 glasses of liquid a day (most of it should be water). When you cut out the fats and sweets, you will be surprised at how good the other foods taste. Even a baked potato can be great. Start exercising. Begin slowly, then gradually increase the time, but do it so regularly that it becomes a habit.

"Moderation is the key to success. Substitute common sense for bad habits. Life for me didn't begin at 40. It began at 80."

DEAR ABBY: Recently at an amusement park, I noticed a group of people waiting in the middle of a line, when one of them broke in. By the time we were even with them (it was a double, divided line), they had all broken in at that spot. When the lines merged, my group was immediately in front of them. Then, one of them crowded in ahead of us. Shortly thereafter, all of them tried to push through.

Thinking they did not understand that this is rude, I began to politely explain, asking if they felt that we had crowded in front. "No, but one of our party is ahead of you," was the reply, "so we can all go." Any further explanation from me was met with anger and insults.

Please clarify this for me, Abby. I always thought that latecomers should go to the end of the line and wait their turn. If I am joined by a friend, instead of causing hostility by letting my friend in, I give up my place in line and join my friend at the end.

Was . . . OUT OF LINE?

DEAR OUT OF LINE: You were not out of line, but you were outnumbered. Too bad no security guards were present at the time. Free-for-all fights have been known to erupt due to that sort of rudeness, but given today's climate for unpredictable violence, you used good judgment in not making an issue of it.

Everything you'll need to know about planning a wedding can be found in Abby's booklet, "How to Have a Lovely Wedding." To order, send a long, business-size, self-addressed envelope, plus check or money order for $3.95 ($4.50 in Canada) to: Dear Abby, Wedding Booklet, P.O. Box 447, Mount Morris, IL 61054. (Postage is included.)