Apologies - I got called away and didn't have time to finish typing my response.
If you don't understand employment law, then you will need to be ready for undertaking a crash course. The tribunal will allow for your lack of experience in the process - but they will not help you in any way with the law.
The biggest mistake that people make is thinking the law is about being "fair" - it absolutely isn't. You must present a coherent legal case, and most people believe the law says things that it doesn't. For example, everyone knows that the DDA says that employers must make reasonable adjustments for disabled employees. No - it doesn't. The DDA was repealed in 2010, and replaced by the Equality Act, and neither of them say that. They say that the employer must consider reasonable adjustments, which is a whole different thing; and having a disability isn't enough - it must be a disability within a set criteria. That's just one very brief example, and under that basic explanation there is shed loads of detail. To argue at tribunal successfully you need to know or learn the law as it pertains to your claim.
The second biggest mistake people make is thinking that tribunals award lots of money. They don't. The stories people hear are heard because the awards are exceptional. The average award is very low - for unfair dismissal the median award (which is the most accurate indicator of likely outcomes, the average award being skewed by the few high awards) is less than £7,000 (2021). For sex discrimination it's less than £10,000.
The third biggest one is one @rose69 's friend probably made - an offer of a settlement is most often made on economic grounds, as a cost saving over legal bills. Do not assume the employer is on the run or that they will offer more or you will win (or win more).
As a union officer I do know a lot of people who have gone to tribunals over the years. I will warn you that even those who win often don't think it was worth it - and that is with union support and legal work.
I am not trying to put you off - if you need to do this then you absolutely must. I totally understand that. But I do want to give you what you asked for - honest experience.
Finally, if you think about no win no fee ambulance chasers, be very, very careful. There are a lot of pitfalls that people aren't aware of in such generous sounding offers. I know enough cases of people who ended up with financial losses as a result of going down this path, so do be very cautious, check everything and do take advice before signing up for anything. Employment tribunals (assuming you win) almost never award costs, so your solicitors costs will come out of your win (and in some cases costs exceed what is won). And if you find it all too hard and pull out most will charge you.
The best piece of advice I can give you is, whatever you decide about this situation, when you return to work join a union and stay in a union. That isn't a carte blanche for legal costs - unions won't pursue cases that have little prospect of winning. But they will ruthlessly tell you if you don't have a hope, will support you if you do, but also can intervene to support you and try to head off you needing them for a tribunal. All workers are entitled to join a union whether or not one is recognised by the employer, you can join any appropriate union you want, and you do not have to tell the employer you are a member.