Agree with all that's been said so far. Try the simplest approach first and progress in complexity from there if required:

1. Try higher filters in your enlarger with standard paper developers like Dektol, LPD, etc and Ilford VC papers or maybe try Oriental VC papers
2. Add a higher contrast developer
3. Switch to condenser enlarger if available
4. Intensify the negative (selenium can help a little if the negative isn't too thin, or use a formulated proportional or super-proportional intensifier)
5. Make a contrast increasing mask or even dupe the negative to make it more contrasty (these are more complicated last resorts)