If you can't get a retirement visa with your husband you can get a agent to get you a Destination Thailand Visa DTV last for 5 years but I believe you still have to do 2boarrd crossing a year
If your both over 50 retirement visas but get in once your in the country. Under 50 DTV is the new one both are best done through a agent not because they hard to do but immigration generally will send you from pillar to post because there get nothing from where as a agent might help immigration with brew or two
If you have the money in bank do it yourself. Go to bank first thing in the morning get a letter and update pass book. Then go immigration get the form. The office to the left hand side of immigration will fill the form in for you if you have difficulty with it. They also make sure you have all the right copys of passport stamp from when you entered and front page and a passports size photo of yourself. Cost about 500 baht 1900. Baht total 2400 baht. Real cost including taxis would be about 3000baht . First. Some agents charge