Generally speaking I would expect you to be covered by your spouse but ask - there are a few companies that don't cover spouses or make them pay 100% of the premium. If that's not true you're protected by both the ACA and HIPAA (the older law that stopped group plans from rejecting anyone for preexisting conditions).
Permanent residents are eligible for Medicaid though they may have to have lived here a certain number of years. Eligibility varies by state. states are required to have medicaid for 4 classes, all linked to income: pregnant, children, disabled, and elderly. The ACA expanded this to all people under a certain income level if states accept the expansion. But it is always income linked even if your disability would be qualifying, and in some states that income would be quite low.
Some other non-citizen visas may also be qualified residents for Medicaid purposes, but this gets complicated.
Since your disability exists prior to US entry and you don't have 40 quarters of employment, you wouldn't qualify for SSDI. If you later develop some other condition, or it worsens and makes you unable to work, you might. This is important because receipt of SSDI makes you eligible for disability Medicare.
If you came to the US you would be relying on your husband's insurance or the marketplace.
If you go to GoodRx you can see list prices of medicines, though this does not always correspond to what your insurer/PBM (pharmaceutical benefits manager) pays the pharmacy, and of course not what you pay out of pocket, which varies quite a bit. For example, I pay $8 for a month's supply of any generic (there are some that actually cost less and I just pay that) and 20% of the cost to a max of $100 for any brand name on the formulary. (90 month mail order supplies are the equivalent of 2 months retail pricing.) So generic meds can be quite inexpensive but brand name drugs add up. For some popular and expensive drugs, the manufacturers offer coupons that lower the cost. I use Ozempic for diabetes and the coupon takes me to $75 for a 3 month supply.