Update:
I finally got it working, if someone is having the same problems that i had here is what i used:
radio.initialize(FREQUENCY,NODEID,NETWORKID);
radio.setHighPower(); //uncomment only for RFM69HW!
radio.writeReg(0x03,0x68); //RegBitrateMsb 1200 bitrate
radio.writeReg(0x04,0x2B); //RegBitrateLsb 1200 bitrate
radio.writeReg(0x05,0x00); //RegFdevMsb 2000
radio.writeReg(0x06,0x52); //RegFdevLsb 2000
radio.writeReg(0x19,0x40|0x10|0x05); //RegRxBw DccFreq:010, RxBw_Mant:24, RxBw_Exp:5
radio.writeReg(0x18,0x00|0x00|0x01); //RegLna LnaZin:50ohm, LowPower:Off, CurrentGain:MAX
and then
if (radio.sendWithRetry(GATEWAYID, payload, sendSize,2,200))
Serial.print(" ok!");
else Serial.print(" nothing...");