Mer, SSI has a ceiling. I think they do give cost-of-living increases...though we on SS are into our 2nd year without a raise. I got SSD...was told I didn't qualify for SSI. But my SSD is what I would've gotten at full retirement age. That manages to cut my food stamps to $16 a month...but it still comes in handy the end of the month. I take everything I qualify for. Look into getting Life Line credit for your phone. I'm not sure if it covers cell phones (I know it wouldn't cover both a cell and a landline), but I pay just the taxes...which amounts to $6.50 a month. I live in a senior apt. complex where rent is $30 of yearly income (actually more like 25% as they give a utility credit...and also lower your rent if Rxs and OTC drugs paid out of pocket equal 3% or more of income.
Also look into LIHEAP--Low Income Heating and Electric Assistance Program. What they will give you in credit will depend on income and utility bills. A little over a year ago, they gave me enough to carry me for 3 1/2 mos. I'm waiting to apply again when they come here for folks to do the application process. This can only be done once a year.
Here in Jax, FL, we have a handicapped van service which has door-to-door pick up and drop off for a small fee. I take this as I can't walk the distance to the bus stop. There are also shuttles and regular buses...where I can ride free...though I'm better off with the van service.
Use the dollar store, especially for foil pans, party stuff, cards, cleaning and kitchen thing. Everything is a dollar. Also use thrift stores. Most of my wardrobe is from thrift stores. Use coupons! There are various sites online where you can print out coupons. The Sun. paper is usually full of them. Use a coupon for a sale item and you end up paying very little. Do Buy One, Get One if it's something you use all the time. Try store brands, which are usually cheaper than brand names.
When I got sick from hep C and had to go P/T, I learned how to live for less. You'd be amazed at the help available.
Hugs and best of luck! You can do this!
Connie