To buy or not to buy

Need some advice please currently have a mortgage on a property in 50% neg eq. Had a brain haemorrhage last year insured myself for 100k which paid out . Have sale agreed on a property ( good rental area ) plan was to live in new property and rent apt . That has changed now as living on my own with child . If I rent property with no mortgage . That will pay mortgage on current apt . Will I lose my social welfare payment currently illness benefit . Not in position to return to work yet due to disabilities .. Any advice would be great .
Regards
Peppapig