What should i do about a driving without due care/attention letter?

a few months ago i was involved in a collision that ended in my car being wrote off,initially, the other driver was driving dangerously which caused me to swerve and nearly crash,he drove off at speed and i caught up with him to get his reg number,he didn't take to kindly to this and repeatedly hit his brakes,as we pulled along side off him,admittedly furious and swearing,he side swiped us and again drove off at speed,i followed him at speed to catch up(all of this i might add no faster than 20mph)he again slammed on his brakes and i rear ended him,Ive received a letter from the police saying they believe from evidence i may of committed an offence of driving without due care and attention,as an alternative to court i should pay 152 for a driving course,my husband and i since then are on benefits,as my partner came out of work due to ill health, i cannot afford to pay for the course,but i am terrified of going to court,and this is making me ill with the stress of it all,what should i do?