This reminds me of the Friends episode where Phoebe announces her New Year's resolution is to pilot a commercial jet. Unlike Chandler, I'm not resolved to remain tight lipped on the subject of trying to become a psychologist without a degree.
First, psychologists have a protected title in the UK. You can't call yourself one without a psychology degree. You can't access training without a psychology degree.
Second, if you think psychology is so easy that it doesn't require specialist training, usually with a hefty research component attached, then you don't understand the profession very well. You may well like the idea of being a psychologist, but you may not like the reality much at all.
Third, if you want to change careers, there are sacrifices involved. You may have to drop down a pay grade or five. You may not be able to do it at all if your mortgage is the greater priority right now. It may be that you have to strip your lifestyle back to the bone to be able to do it. That's what I've done to achieve a career change.
Fourth, degree doesn't necessarily mean three years in the initial instance if you already have a first degree. You can do a one or two year masters to convert to psychology. There is also government funding available in the form of loans if you don't have a master's already.
Fifth, your experiences in work will count. If you want to be a psychologist i.e. go through the professional training programmes etc. then you may find that you are already able to evidence a number of the competencies from your work. However, if you want to fulfil the entry requirements for clinical psychology or similar then you will need something along the lines of 12 months clinically/educationally/forensically relevant work experience. There is no getting around that.
This may be something you need to think carefully about. I recommend going to the ClinPsy forum to find out a bit more. You may also want to consider alternative career changes e.g. counsellor, speech and language therapist, wellbeing practitioner, medicine etc. for which the training period is significantly shorter than psychology. But you are probably going to need a degree for any of those. No shortcuts.