As Ben said in the comments, Citizens Advice is your first stop.
It sounds like the company is having a cash flow issue at the moment. If you go in, crack on, and put some faith in your boss to solve the problem, chances are that your loyalty will be noted and appreciated.
If there are other things giving you cause for concern at work, then maybe evaluate your position in the company. Keep working while you search, it will reflect well on you with future employers.
Either way, it is in your best interest to go in to work.
The reasons I suggested giving the company the benefit of the doubt in the short term are:
- They paid some, suggesting there is still some cash around
- They explained the situation openly
- OP should still be going into work until this is resolved (either by leaving or the company finding its feet) and a relaxed attitude is best