What other options do I have if my employer says I have to resign because my long term leave has expired?

Was it maternity (up to 12 weeks if you qualify per fmla) or workers comp (see a workers comp attorney but think that could be upwards of a year was there a mutual agreement that you could be off (under a separate theory), and that the company is in breach, since you came back per the agreement, and now they don't want you?

You have no option, if you are unable to return to work. Being on Long Term Disability does not protect your job. You could refuse to resign, and let them discharge you. If you are unable to work any where, you will not be eligible for unemployment benefits.If you are able to work somewhere, but not at your old job, you MAY be eligible for unemployment benefits. But, so long as you are on a leave at your own request, you will not be eligible for unemployment benefits.

Not much, you are paid to work, and not to be on disability. If your benefits have run and contracts with you honored you have no legally cognizable complaint.

You could be terminated for not showing up to work when required.

You should quickly hire a lawyer and try to preserve your job. Obviously, you probably have a disability, but if you are unable to perform the important functions of your job with or without accommodation, you may lose your rights. We would be happy to meet with you before the employer terminates. Once terminated, it makes the legal situation very difficult.