A lot of very unkind responses here, but I'm guessing that your baby had a bad reaction to the first set of jags. You certainly weren't alone, the Men B one is pretty brutal with pretty high rates of serious adverse events compared to other vaccines (see the review below, stating rates of SEAs as 5.4/1000 for Bexsero compared with 1.2/1000 for vaccines generally).
www.ncbi.nlm.nih.gov/pubmed/29371070
Unfortunately, the Men B vaccine has relatively low effectiveness (again compared to other vaccines on the schedule) and doesn't give adequate protection unless the full course is completed as Sidge says above, so if you want protection against the strains of Men B covered (with some likely cross protection to Men W and possible Men C strains), for at least a couple of years (until your baby is out of the highest risk zone anyway) you will probably need to finish the course.
You don't have to give it with the other jags though, and a sensible Immunisation nurse will be happy to spread out the vaccines. Thankfully, it's not a choice between sticking to the schedule and not giving them at all - you are perfectly within your rights to take another path that you feel is safer (reduced side effects while still giving protection against disease). This is pretty common practice now and loads of people do it, so I'm fairly confident you won't be the first. In fact, the Bexsero product insert itself indicates that giving it alone reduces the risk of side effects:
"Due to an increased risk of fever, tenderness at the injection site, change in eating habits and irritability when Bexsero was co-administered with the above vaccines, separate vaccinations can be considered when possible."
www.medicines.org.uk/emc/product/5168/smpc
Personally, I chose to spread out the jags to reduce the chance of side effects. The Men B one alone still caused high fever (even with paracetamol) but it wasn't scarily high like a lot of other parents I know. It's not "antivax" to ask perfectly legitimate questions about vaccines when you've had a bad experience, and trying to silence ANY critique in ANY circumstance is really not helpful.