(edit title) Breach of contract rental and thievery Options

[icyk]

Hi,

I am currently renting a room in Stockholm.
I am living with the lanlord (That I will now refer as X) and the relations are really bad.
I informed X that I wished to leave, X is now really angry and told me I cannot leave until I pay like 6-7 month of rents.
I send a termination letter and informed that I will leave in 3 month.
X now only talk to me but only to harass me (telling I am breaking stuff that are worth over 1K sek, but well I have proof I didn't), in my opinion, X tries to create fake evidence by messaging me to keep my deposit after I leave.

The deposit is worth two month of rent.

Now X has stolen official and legal document that postnord gives me when I sent the recommended letter to inform I am terminating the rental contract in three month.

Since that, X never went to get the letter and never answer my message. X though still continue to send me message to harass me and constantly lying.

Is this thievery a legal reason for me to leave and not pay anymore the rent for the next 2 month ? Or even if X stole my legal document, I am still obliged to follow the contract and stay two months ?
(What I mean is leaving two month earlier my period notice due to the thievery, which in my opinion is a breach of contract, I am not feeling secure anymore here and living there is really making my life difficult, and then get back my deposit either by arrangment or legal justice)

Hope somebody will be able to help me.

Thank you