It is very possible they are trying to get you to retire now by making life miserable for you. It's just the harsh reality. They can hire a younger person for much less money. For your protection, I would write down your job description and add in all the additional responsibilities above and beyond what you were hired for. Then if push comes to shove, you can present it to your manager and HR.
If you absolutely need to work another 2 years it's important to try to take things in stride for your own mental health, which MUST be the most important thing in anyone's life. Try to go in with the attitude that you are a good worker and can only handle so much work in one day. Try to relax instead of fretting about getting things done. Hate to sound cliche but one thing at a time and one foot in front of the other. That's the best way to cope with an overwhelming workload.
I was forced to retire early because of a personal situation at home. I have no regrets. I'm not even able to collect SS yet. If you have some money saved and you know how to live modestly and save, it's very doable to retire early. I'm leaning towards collecting SS sooner rather than later because like John said, we don't know how long we have.
If it is, indeed, your employer's intention to force you out, don't forget to negotiate a good severance package for yourself.