Joint and several liability. What should I be careful about?

My friend asked me to make a solidarity with him on a deal he made. I signed without thinking, because I kept on it and could not refuse it. However, I did not investigate well enough exactly what it means to be a solid debtor, but that's what it turns out to be.
What is solidarity responsibility?
In the case of joint and several liability, several debtors owe the same thing to the creditor. This is my case - my friend Peter needed money, so he signed a loan agreement with his neighbor Ivan. Since the sum was not small, the neighbor Ivan asked my friend to find a solid debtor. And that's where I got in - I signed the loan agreement as a solid debtor. My friend took the money and spent it quite quickly. However, it was agreed in the treaty to return the money to Ivan on March 7, 2018, which is less than a week away. It turns out that Ivan can ask for money not only from Peter, but from me. Yes - although I have not spent a penny of that amount, if Ivan asks me to return the money, I have to do it.
How can joint and several liability arise?
One way is by contract, as in my case - I myself signed the loan agreement as a solid debtor.
The other way is more special - the law itself provides for joint and several liability. For example, if I make a contract for making, and under this contract, two sculptors are obliged to sculpt a female body of clay. Then these two sculptors are jointly and severally liable, and in case of failure to fulfill their obligation, I can claim damages from each of them. Here is another example - when trespassing (say in a road accident) when injured by several people, they are jointly responsible for the damage they cause.
When it comes to a commercial transaction and two or more persons are obliged to do so, they are jointly responsible - here again the law itself provides for this rule.
Solidarity action
So - it turned out that Ivan could ask for the money to be returned, both by Peter and me. Moreover - he is not obliged to ask for the money first from Peter and then from me. He can ask them directly from me. If Ivan wants his money from Peter, but I offer him a refund, he has no right to deny me.
And if I gave him only half of the sum borrowed? In this hypothesis, he can safely look for the remnant of Peter.
There is one detail, though - the neighbor in question, Ivan, owes me 500 leva because I sold him a TV before. Now that he has filed a lawsuit against me and Peter for the return of the loan money, I can make an objection to interception. So if I and Ivan be ordered to return the money that Ivan is borrowed (5,000 lev), the court upheld the objection of set-off, we will not owe 5000 lev and 4500 Levs In the opposite situation - if Peter had to he takes from Ivan 500 leva (because he sold his mobile phone for example), even if I know about this debt, I can not object to interception.
I also have to know that Ivan can only take action against me. He is not obliged to bring a claim against me and my friend Peter, but he can choose - only against me, only against Peter or both of us. This is because we are joint debtors.
Besides, I have to pay attention to the following - If Ivan has simplified Peter's duty, then that remission will also benefit me - that is, and I will no longer owe it unless Peter has retained my rights to me. The remission is a contract between creditor and debtor by the creditor actually renounces his claim (in our example, this would mean Ivan to give up money that Peter should he return).
And what about prescription?
As has already become clear, I signed the loan agreement as a solid debtor. Now, let's imagine the contract says that I owe money back only if Peter does not pay the whole month after the agreed date. So, Peter had to return the money on March 7, 2018. If he did not return them until April 7, 2018 - I owe him with him, too. I become a solidary debtor. All this means that the claim against Peter is due on March 7, 2018, and at this point Ivan can only ask for money from Peter. My claim to me becomes payable on April 7, 2018. The limitation period begins to run from the moment the claim becomes due.
Important! If the statuary of Peter has expired, this is not an obstacle for Ivan to seek the return of the money from me. In our example, taking John to Peter was extinguished by 5-year limitation period, it expires on March 7, 2023 After having missed the deadline for appealing against Peter, Ivan could bring such against me no later than April 7 2023
How can I protect myself?
In order not to bring an enforcement action against me, I paid to Ivan the money that Peter had borrowed. Once I have paid I automatically acquire rights against Peter and Ms


Joint and several liability. What should I be careful about? Joint and several liability. What should I be careful about?