I'm impulsive too, so I get what you mean. But maybe the next step for you could be doing some kind of healthcare/hospital volunteering or work experience (you may need to do this to even get onto a course in the first place? I don't know, not my area) and seeing how you find it? You could do this asap to scratch the itch of feeling like you're doing something, and to meet some people already doing similar work, then take it from there.

You've done all of that after only a few days of considering it? That's some impressive pace!

I wouldn't keep looking for other things if you're excited about this. I think I'd just try to slow down a little, take it one step at a time, and let it sink into your mind a bit further while you do much more research. Read some books about it maybe. Have you read memoirs about being a paramedic? Blood Sweat and Tea by Tom Reynolds is meant to be good, and Can You Hear Me by Jake Jones.

When's the application deadline for the courses? Have you spoken to family/friends/a partner/people who know you really well about what you're thinking? Sometimes it helps to hear someone you love say "Oh yes, I can totally see you doing X".

The only other thing I can think of would be to talk to some paramedics or do some shadowing.

If you signed up now, what would the consequences be to back out ie can you sign up with no penalty for a few months and just sit with decision to see how it feels?

Sounds exciting OP! You really need to look at what you need to get onto the glide green programme mind, and double check that whatever you do meets the university's you are interested in applying to requirements. University admissions are normally very good for this.
Getting some experience in a healthcare setting is a great idea. You need to show your 'people' skills. How you cope in stressful situations etc.
Have you looked into the pathway of getting in via being a band 4 and getting on the job training?
I often work in ED. A lot of amazing paramedics are increasingly frustrated at spending whole shifts (and more) parked outside ED with their patient awaiting a bed in ED. Shifts often run over the schedule. A lot of mental health call outs I believe as well. Speak to as many people doing the job as possible. Try and get a real insight for it.
I'm guessing an access course would also open up the doors to other health related courses as well?

Access courses generally start in September of each year so you’ll have a while, although the application deadlines will vary college to college.

I agree with PP that you need to do some healthcare work exp and speak to paramedics if you can to make sure it’s for you. You’ll be able to pull out of most access courses up until the start date without owing fees.