Carbon fibre is very very repairable in competent hands. You could easily effect a safe repair yourself, but it wouldn't be as good as the original laminate structure, heavier and less good looking.
By far the cheapest way to get your bike up and running again would be to get it repaired. A good repair centre will also be able to match the paintwork as well. I know GCN can be a bit maligned but they actually do put out some good content now and again, a video they did recently on repair is
here.
A new frame comparable to your Merida will be upwards of £500. I'd also contact your home insurance provider, if you put the bike on your insurance then given the choice of paying out for a new bike or the cost of repair they might opt for the latter.