You should talk to a lawyer right away about the following options:
* If you owe rent between March 2020 and December 31, 2021 due to the pandemic, you have the right to a payment plan. Some counties also require the landlord to offer you a chance for mediation. In any situation, you can try to negotiate with the landlord not to raise the rent for a certain amount of time. If you and the landlord do agree to this, try to get it in writing.
You can also ask the landlord to change the date your rent is due, if it would help sync when you get income with your ability to pay rent. This will also limit the landlord's ability to charge you late fees. Read Can I change the date my rent is due? to learn more.
If you believe the landlord is raising your rent to try to get you to move out because your income comes from government assistance, you may have grounds to sue the landlord and ask for four and one-half times the monthly rent of the place, plus court costs and attorneys' fees. ("Government assistance" here means SSI, TANF, and so on.) RCW 59.18.255.
*You might also have other options. Ask a lawyer if the Washington Law against Discrimination (RCW 49.60), the Fair Housing Act (starting at 42 U.S.C. 3601), or the good faith requirement in the state Landlord Tenant Act (RCW 59.18.020) can help you at all.