If I’m currently living in a home but am not on the lease and my roommate who is on the lease is trying to give me 48 hours to move out, what can I do?

I'm assuming that you paid rent. In that case, since you are not on the lease, you are your roommate's "subtenant" . Accordingly, you must be given a 30-day "notice to vacate" the premises (or "notice to quit"). If you aren't out by then, your roommate will need to file a "unlawful detainer action" (i.e. an eviction lawsuit).

Also, you could be considered to be a tenant (as oppossed to a subtenant) if you paid rent directly to the landlord or if the landlord put (or allowed you to put)your name over the doorbell or on the mailbox. In that case, your landlord would need to file for the eviction since only landlords can evict tenants. In other words, your roommate would have no right to evict you.

As you seem to be aware, you have rights in this situation since your roommate is not following legal procedures. In fact, you could be entitled to recover damages, especially if your roommate tries to remove your belongings, changes the locks, etc.

At this point, you should try to speak with an attorney who handles landlord-tenant cases. You can also see if there is a tenant's rights organization who can give you more information. Also, your local social services department may know who can be of help. Finally, see if there is a law school nearby since they run free or low cost clinics that handle these type cases.