Reference help for a drop-out

(Original post by CrysCross)
I apologise if this isn't the right section to ask this in, it's my first time asking anything on this site and I don't really know my way around it yet. The issue I'm facing just now is to do with references for college. Due to several mental health issues, I was forced to leave school at 15 partway through completing the necessary qualifications to get into Uni (I'm from Scotland and our education system is different from elsewhere in the UK so I'm trying to word this as inclusively as possible). I am now 17 and applying to college in hopes of attending Uni in a year or two. The problem is, the colleges I applied to are all asking for references, something I don't have any access to. I've been out of school for two years and had a spotty attendance record before that due to the previously stated health issues. The only job I have had was at my grandparent's company (family are not allowed to be a reference) and I only recently began voluntary service, not long enough to have a contact there with a valid enough opinion of me to use as a reference. The reference is undoubtedly important no matter what your grades are like, but my first choice college has slightly higher entry requirements than what I have (I have already passed the first stage of applications and am scheduled for an interview so they are lenient enough to offer me that) and so the reference is all the more important. My family aren't of any use either as they are all telling me to simply use one of the grandparents I worked for because I have a different surname and, according to them, 'nobody follows these up'. Obviously I rejected that idea. I wouldn't even contemplate the idea of using a distant relative nevermind a direct one, add on to the fact that they are listed as some of my emergency contacts (again, due to health issues). My previous school is out of the equation, as is my employer and my health officers (as to why that's a whole other story filled with clerical issues, careless administration and their apparent inability to use anything other than the postal service in way of contact). My volunteer officer has only just met me and my family is too 'just try it, what's the worst that can happen' to offer any solid advice. The few friends I have are either in apprenticeships, applying directly to Uni or are already in employment so no one is in the same boat as me. Any help is appreciated and thanks in advance.