Whether it's beyond hope or not will really be limited to;
How is the body?
Has everything else been maintained as required?

Worst case, you may need the transmission removed and rebuilt. That's certaintly no crime for a fifteen year old car. Let's use the number $2000 as the price for the tranny rebuild. If you saw an identical car for sale, and the price was $2000 would you be tempted to buy it?

If you went out today and purchased a new car, in the $15,000 price range do you realize the "depreciation" is going to be $3000-$4000 just driving it off the lot?

Now all of that aside, exactly what does your transmission do? Does it simply not shift to the highest gear, which would be OD I believe so it simply gets to third and stays there? Or does it slip, which means it attempts to shift but the clutch being commanded on is worn out and cannot apply. The accompaning symptom is the engine starts to race when that shift is attempted.

What happens if you drive the car in "3" instead of drive?

What did the fluid look/smell like before it was changed? What does it look/smell like now?

Many people bail on a car like this way to early IMO. Properlly repaired you can very likely expect several more years of service from it, without a guaranteed monthly payment associated with a new car.

Sir, my car is not very pretty to look at anymore but I am very attached & it has the greatest motor. I want to get it fixed but I am afraid I cant afford it at this time.We are having a very hard time.
When you start to drive, it jerks into the first gear & just wants to rev after that. I havent tried it in the last gear but my husband said it was doing the same thing.It has all just started recently, within the last few days.
My husband said the fluid smelled burnt.
someone said it sounded like the modulator valve. Could that be the problem?
Thank you.

Jerking into first gear can be caused by a vacuum modulator valve that has lost it's vacuum signal. This can happen if the valve starts to leak, and the transmission fluid gets to the vacuum hose. The hose swells, gets soft and eventuakll falls off of the modulator. You should even see a vacuum hose all the way up at the engine that is soft, and has oil in it. While it will cause a very late shift into second gear and third gear, it actually would not prevent the transmission from shifting. But you risk over-revving the engine to find out. (You might have to go over 40mph to get second gear, just like a full throttle acceleration)

If you get this to a good shop, one that is experienced with your car they should be able to figure it out easily.