I Am On The Following Medications And Desperately Need To

I am on the following medications and desperately need to add propranolol into the mix. First I ask is this safe to do? Medications currently on:

- Venlafaxine (75mg a day for past 2 years)
- Diazepman (20mg as needed, last dose 2 hours ago - no other doses within last 7 days)
- Alprazolam as needed ( last dose of 2mg 1 hour ago - no other doses within last 7 days)

And hopefully, soon to add in:
- propranolol (40mg tablets prescribed - but haven't ever taken it before)

I have a significant tolerance to opiates / benzos in general and never use for recreational use. To give you an idea as to the tolerance, to begin have any noticeable recreational affects I would need the following dose of each medication (when taken alone)
- Oxycodone: 100mg oral followed by 40mg an hour later.
- Diazepam - 40-50mg and I'll be feeling very light and silly. Won't pass out though.
- Xanax - 2mg to calm me down. Maybe 4mg to ensure sleep.

The mix I am currently on is fine, my breathing is fine (perhaps a little shallow but nothing out of ordinary). I will not be taking any more benzos tonight, but may have to take 10mg more Oxycodone, which will be fine.

I .. NEED to take some propranolol to take away the severe anxiety I am still experiencing. Along with sensation of heart palpitations - heard in my ears as if it's pumping too fast/hard.

I am feeling like running into a bomb shelter and crying but I have to go out within the next hour to pick up my daughter (walking of course, not driving) and need to know if it is safe to take the propranolol, and how much for first time considering my current cocktail (I am guessing 10mg to start?)

I won't be taking more oxycodone until after I have a clear understanding of how the propranolol takes effect.